INSPECTION OF THE scene OF CRIME
AND INSPECTION OF THE CORPSE
Successful crimes disclosure, inveighing against criminals depends on that, as skillfully, in good time and of high quality will be carry out primeval investigative actions and, specifically, the most important of them – inspection of the scene of death. Inspections of the scene of death generally, and attached to investigations of murders especially, are very necessary and in the same time difficult investigative actions video .
Importance of the inspection of the scene of death and the corpse is extraordinarily large. It determines first of all by that, that inspection is the most important source of evidences. One of founders of home criminalistics, professor N.P.Makarenko, wrote, that inspection of the scene of death and the corpse is the “headstone of the investigative actions”.
Successes of the investigation of the crimes against citizen’s lives and health frequently are found in straight dependence on the quality of inspection of the scene of death.
Results of the study of criminal cases about murders, closed as a result of unestablishment of guilty, showed, that the quality of investigation in these cases was very low. Specifically, in 17% of studied cases inspection of the scene of death took out of time, in 27% of cases was investigated only the corpse finding place, and ambient locality or furniture was not inspected, and in 17% of these cases the corpse in it’s finding place was not inspected.
It’s known, that some important evidences can be got only attached to inspection of the scene of death (inspection of the place, traces or oddments of blood, sperm, hair etc.).
The scene of crime is a territory or lodging, where directly took place an event, which is a subject of investigator’s inspection. An exclusion are cases, when the corpse was found not in the place of crime, for example, of the murder, but elsewhere, because fact of his finding always considers as an event, so place of it’s finding also will be an event place. Borders, within the pale of which have to be carry out inspection of the scene of death, in each concrete case determines by investigator, proceeding from peculiarities of the given event.
Inspection of the scene of death is an investigative action, based on the direct perception, study of the scene of death furniture, exposure, fixation and withdrawal of different material evidences, clearing up the event disposition, clarifying of criminals personality motives of the crime (D.P.Rasseikin, 1997). V.P.Kolmakov (1999) underlines, that the main aim of the inspection of the scene of death is clearing up of all of the circumstances, which are important for establishment of truth in the cases. inspection of the scene of death must be objective, systematic, full and careful.
Superficial, formal examination of material traces and furniture can relieve inquest of important information, to delay or to make possible crime investigation.
Taking of inspection of the scene of death and the corpse in it’s finding place regulates by some articles of criminally-judicial code of the Ukraine (CJC): 190, 191, 192, 315, 127, 128.
According the article 190 of CJC of the Ukraine “with view of exposure crime traces and other material evidences, clearing up of crime furniture and also other circumstances, which are important for cases, investigator carry out inspection of the locality, premises, articles and documents. About the results of investigation composes protocol.
So, inspection is a judicial action, and this is primary and pressing investigator action, carry out by investigator, which is the main independent figure and is quite responsible for its organization and results. Everything, that happens or appears in the investigation place, notes in protocol, which investigator composes during inspection.
According the article 227 of CJC of the
Protocol is a basic method of the inspection results fixation. There can’t be deductions in it, but thoroughly are described all actions of investigator, everything expressed in act of examination in that appearance, in which was observed in the investigation moment, counted and described all withdrawal during inspection. Protocol encloses photographs, plans, event place schemes, traces impresses etc. (watch beneath). In the end of protocol indicates, where sent the corpse, what material evidences withdrawal.
Photo of the scene of crime
Scheme of the scene of crime
According the article 191 of CJC of the Ukraine, which is called “Inspection taking order”, inspection carry out in presence of not less than two witnesses and, as a rule, in the day-time. Witnesses are the persons, which are invited by investigator or by inquest organ for participation in carrying out of some actions, foreseen by judicial legislation: inspection, search, withdrawal, taking investigative experiments, corpse exhumation etc. Execution of witness debts is a duty of each citizen. Witnesses can be not less than two adult citizens, which are not interested in the final result of the case. They certify the facts, maintenance and actions superventions, attached to carrying out of which they were present.
During premises inspection have to be present a person, which occupies the given premise, or responsible spokesman of organizations or enterprises. For example, inspection of the shop in case of stealing must be carrying out in presence of the manager of the shop or other materially-responsible person or spokesman of suitable haggle.
Inspection of the scene of death must be carry out in good time: the earlier after crime, the better, because traces can be destroyed after some time. Such inspection is diserable to carry out in the day-time attached to natural illumination. Inspection at night has a row of negative moments. If inspection of the scene of death carry out at night, that was caused by its urgency, then it must be carry out secondly in daily time to find, what was admitted at night.
According the article 191 of CJC of the
Most often such specialist is a specialist in the industry of methods, engineering, and crimes dissection tactics, which knows the ropes in exposure and withdrawal of different crime traces, can give them correcting estimation. Often as a specialists invite an engineer from accident prevention, doctor or any other specialist.
Article No 191 of CJC of the
Article No 192 of CJC of the
It is desirable, that in inspection of the scene of death in case of the corpse presence participates judicially-medical expert, and simply doctor, because practice shows, that participation of the doctor, which is not a specialist in judicial medicine, is ineffective.
External (primary) inspection of the corpse is a composing part of inspection of the scene of death. Such inspection with participation of judicially-medical expert or doctor does not replacement inspection or autopsy for determination of the cause of death and settlement of other questions video .
Judicially-medical expert or doctor of any profile attached to participation in inspection of the scene of death works as the specialist, but not as expert, because there’s no examination in the scene of death. Special medical doctor’s knowledge makes investigative actions, specifically inspection of the scene of death, more qualitative and more effective.
As a participant of the investigative action doctor does no compose any documents, reflecting his activity. Everything, that carries out and expresses in the scene of death, as already remembered, investigator fixes in the inspection protocol. Doctor helps the investigator to compose it, specifically attached to describing of the corpse, different traces.
After finishing of inspection of the scene of death and the corpse with signs of forcible death investigator has to write a decision about destination of judicially-medical inspection or to compose direction and to bring up to the expert concrete questions for their solving.
The tasks of inspection of the scene of death are clearing up some questions, which help to disclose crime, namely:
1. Had a place crime in given case or no, in what essence of investigated event?
2. Was the crime there, where takes place inspection of the scene of death, or elsewhere?
3. What ways had penetrate to the scene of death and leave it persons, that took part in the investigated event?
4. How many persons were there in the event place, what are their typical signs, who exactly was there?
5. What was the aim of the event participants?
6. How long were on the scene of death participants, specifically – criminal and victim?
7. When did the event take place?
8. What objects or traces had the criminal omit on the scene of death?
9. What traces on the scene of death could remain to the criminal?
10. Who and where from could see or hear that, that happened on the scene of death?
11. Exposure, collection, fixation, previous research, estimation and withdrawal of different traces and material evidences etc.
According results of inspection of the scene of death an investigator efficient:
advances versions about event, organizes their verification;
makes supposition about person effectuating a crime;
organizes pressing arrangements for search and delay of the criminal;
an order of investigation, including taking of different examinations etc.
Two basic methods of inspection of the scene of death are contradistinguished : objective and subjective.
Objective method of inspection – it is full, successive, detailed, inquiring and describing of all allotments and objects of the scene of death, on which one can express different traces and study of which can give the important data for investigation of the case.
Attached to objective inspection of the scene of death exposes to overhaul all, that is in the place and behaves to event, which investigates. Pay attention to so called “negative” circumstances (circumstances, that contradict to usual event development: presents of wounds on the corpse, but absence of blood under it or around; lack of some clothes damages when the body under clothes is damaged; discrepancy of the distance between earth and attachment place of twine, that forms a running knot and squeezes the corpse neck, and the corpse length with raise hands; lack of cadaverous blots on surface of lower parts of the corpse, when they are on the upper part of the corpse etc.). From one object turn to the following one only after full inspection and describing of the first one.
Subjective method of inspection of the scene of death, which carries out only on evident criminal traces (traces, left by crime subject).
These traces belong to criminal person, so to his action during crime in the scene of death (it can be dragging traces, path of blood drops, traces of means of transport etc.). Subjective method uses in cases, when traces in the scene of death are so fresh and lightly expressed, that following them one can sometimes find criminal and stop him. When this method usually uses a searching dog. Subjective method of inspection of the scene of death is incomplete, limited with borders of the traces, left by criminal. That’s why it can be used only in combination with the objective method: after inspection by subjective method investigator must carry out effectuate, full and overhaul objective inspection of the scene of death. video
In the criminology there is so-called main method of inspection of the scene of death, when a place of crime break up into separate allotments and each of them inspects one by one. Main method of inspection of the scene of death is one of variants of the objective method.
V.P.Kolmakov (1999) picks out two more methods of inspection of the scene of death: method of orientation, which consists in general acquaintance with building or locality allotments, where took place an event, that investigates, and review method, which consists in previous conditions study only in planned borders of inspection. Found traces take care from damages, change, loss.
Process of inspection of the scene of death must be consisted of two stages: static and dynamic.
Static stage of inspection consists in that, that seeing, study and fixation of circumstances and all objects, which are found there, take place without change of their primeval localization and shift. Static stage gives a possibility to imagine completely general circumstances of the scene of death, to carry out photographing, study separate articles and traces before their shift, violation or withdrawal in the act of inspection. So, this is impossible to touch by hands or pincers to expressed objects or traces.
Dynamic stage of inspection of the scene of death differs that in act of inspection objects rationally remove, each separately sight from different sides, express different traces, that can be on them or under them etc. For example, overturning of the corpse for exposure and research in dynamics of cadaverous blots to ascertain prescription of death. This can be carry out only after static inspection, when disposition and state of objects are already fixed. During this have to be carefully with objects and traces, to not to damage them and not to omit on them the traces of hands. For this one have to work in gloves and to take
the objects for ends, ribs or corners.
Static and dynamic stages are correlated, are the parts of the one process of inspection, the process of identification of truth in the scene of death.
On arrival to the scene of death and in process of inspection doctor has such tasks, which have to be settlement in case of presence of the human body, namely:
1. To define – is the finding man alive or dead. If absolute signs of death are absent and suspects imaginary death, doctor must give the necessary help.
2. If a man is dead, to define ascertain prescription of death. Time of death is decided according expressive of supervital reactions and early cadaverous phenomena.
3. To fix in protocol regulation and pose of the corpse, to mark the signs of their change after death or no. Regulation and pose of the corpse have definite diagnostic importance.
4. To check the presence of signs of wrestling and self-defense on the corpse or around, including describing of the clothes state.
5. To express and to describe the external damages on the corpse, to define which implement they could be caused by.
6. To express traces of blood and excreta, hair or other traces and material evidences on the corpse or around, including implement of trauma, to help investigator to withdrawal and to encase them right.
Scene of death one should inspect in some order. It depends, chiefly, on three moments:
on that, where happened an event: in the premise or on court (on the open);
on event character (properties, appearance): murder, suicide, accident, warming, transport trauma, poisoning etc.
on presence or lack of the corpse.
Scene of death: dead body and it’s place
During inspection of the scene of death, located in the premise, at first investigate and describe the entrance (state of the door, locks, windows, small opening window panes, glass etc.); draft a premise plan, make a review photo-graphing, determine an outsider smell of carbon monoxide, alcohol, other matters); check off order or disorder in the premise, if there is a disorder, describe it, for example, overturned or destroyed chairs, sparse things etc. Later conduct successive systematic inspection, on the right side (against the sun or on the contrary), round all premise, and then inspect objects in the center of the premise. Investigate and describe the crime traces, contamination, blot, cigarette ends, torn off buttons, food oddments, bits etc., where and how are they disposed or located, in which state etc. Inspection of the corpse finishes inspection of the scene of death video .
In case of inspection on the locality work of investigator and inspection participants, as a rule, reduces to the external corpse inspection and research of the locality around it, where can be found criminal traces , means of transport, smoking, eating etc. During it it’s important to set, is the corpse finding place the place of person’s death, to find material evidences. In protocol write weather conditions, air temperature etc.
Literature on criminology recommend to carry out locality inspection, going on spiral or on concentric circles, broadening with each circle an inspection radius. Inspection of the scene of death can be carry out from the center to periphery, or on the contrary. Term ”center” means allotment or place, where are concentrated the basic objects, on which criminal actions were directed or stood by supervention of criminal actions (the corpse, break open place, place of rape, overturned car etc.). If it is necessary, the scene of death divide into separate parts, sectors (nodes).
Inspection may begin from the corpse or from ambient locality.
Inspection begins from the corpse, when something prevent to put off this inspection to carry out it later or in the end of inspection of the scene of death, namely: in populous places (stations, fairs, exhibitions, on sporting competitions, beach etc.); on the roads and highways, when the corpse prevents to traffic; when in the summer time corpse independently come to the surface or it drag out from water, and it quickly decomposes.
Inspection of the scene of death have to begin from the corpse’s ambient locality, from periphery, when: nothing does not prevent to the inspection; center of the scene of death is not definite, is possible loss of the traces and other material evidences, that are found on periphery, while traces in the center are in safe; when approach to the center traces on periphery can be spoiled or fully destroyed.
After close-up of inspection of ambient objects as a rule proceed to inspection of the corpse. Orders of external primary inspection of the corpse in the scene of death are the next:
1. Mark, survey and describe a disposition place of the corpse.
2. Fix it’s finding place on attitude to nearby objects or furniture.
3. Describe it’s general appearance, sexual, anthropometric peculiarities, age.
4. Check off regulation and pose of the corpse. Sometimes it’s pose is very typical, that gives a possibility to suppose that or other cause of death or violence appearance. For example, if the corpse lie curled up, this is typical for death from action of low temperature (cold), lustily typical “boxer position” or “fencer position” – from action of flame (to death or alive person), typical is position in the case of murder during rape (part legs, elevated skirt or dress, some disarray etc.), quiet position in the case of death from illnesses, typical position in the case of double suicide, in the case of hanging etc.
5. Survey and describe the clothes, it’s condition, damages and contamination on it, pockets contents. Does not recommend to undress the corpse on the scene of death. Clothes of unknown persons must be well-kept for identification of this person.
6. Inquire cadaverous phenomena, at first early, then late, if they are present, for ascertain prescription of death. If it’s possible, make some supravital reactions.
7. Survey and describe damages on open parts of the corpse (their localization, properties, form, dimensions, state of edges, ends and wounds bottom,
strange inclusions, laying on around them etc.) for establishment of trauma implement and search of it in the scene of death. Also chronicle lack of damages.
8. Express, fix in protocol and withdrawal material evidences (trauma implement, traces of blood, seminal liquid, hair etc.).
During inspection of the scene of death and the corpse in its exposure place doctor can utter to investigator or to other spokesman of investigator organs his thoughts, reasoning, deductions. But it is impossible to utter doubtful thoughts, in such cases that’s better to tell nothing at all.
In the scene of death investigator and doctor have to act in concord, to redound one to another. This is the pledge of successful investigation of each crime, directed against citizen’s lives and health.
During inspection of the scene of death specially carefully have to search, to fix and to describe in inspection protocol different traces, first of all of the man. Doctor have to play an active role in these actions.
At the scene of death such traces are remained:
Traces of the man hands nails one can found on various plastic objects, but most frequently on man (or on the corpse) as a sign of wrestling or self-defense. They are sometimes disposed by groups, are generated in the cases of murders by dint of asphyxiation by hands, in the cases of rape and other sexual crimes on the victim’s buttocks, around the mouth etc. Nail traces are linear, arched (falcate) scratch, which give a possibility to establish infliction of damages by fingers, sometimes – to set coercion appearance.
Traces of the man hands fingers (papillary patterns) one can remain on different smooth or shining objects: on glass, porcelain, faience, plastic, nickel, surface of the door handles, polished and varnish details of furniture etc. They give a possibility to set a criminal person using data of criminal registration or by dint of comparative persons dactylograms research, suspected in this crime. Dactyloscopy behaves to criminalist’s debts. Dactyloscopy makes with special trackcopy film or by special paste, which overtakes like a film.
Traces of the man feet are the traces of shoeless or shod legs. Using
Traces of shoeless legs one can identified a person, which omitted them (on the sole, like on the palms, there are original papillary patterns). The footwear traces give a possibility to identify a footwear, but not a person. Most foam are volumetric footwear traces. The legs traces give a possibility to define the motion, length and width of the step, its corner, stops carriage corner. According these data one can identified a person. According peculiarities of legs traces, omitted by criminal in the scene of death one can make other deductions, for example, about his growth (length of man foot average 1/7 of his growth), about lameness (if the left step is shorter, then the right one, man limps on the left leg), about his weight etc.
Traces of the teeth (bites) can appearance on the man body during fight, self-defense, in case of sexual crimes. Traces from bite disposes on two encounter arched lines like small scratch or wound circled by bruises. Sometimes happen bite off tip or nose ring, part of lip, edge of concha, tip off the finger. Ordinary teeth traces can be found on food : butter, cheese, chocolate, apples etc., and sometimes even on the soap (Yu.S.Sapojnikov, 1998). Man teeth frequently have individual peculiarities, which reflect in the traces. According them one can identify a person.
Teeth marks on the skin
Traces of the blood are the most frequent satellites of the crimes, associated with forcible man death, specifically kills. All blood blots are subdivided into sparks, drops, flows, puddles, blots, impresses, creeks and combined ones. Correcting and full describing and fixation of them in the scene of death is very important for investigation.
Sparks – these are the blots, generated as a result of hit of the blood on surface under sharp corner. They are numerous, shallow, have a form of note of exclamation or form of pear with narrow stretched end, which indicates the direction of the motion of blots. Sparks arise in case of arterial bleeding (chainlet of blots with almost identical dimensions, with almost same interval, which can fly away on distance near to 2,5 meters during gashing of blood), when blows on blooded body or object, on accumulation of blood, attached to
Dismemberment of the corpse, attached to sharp shaking of blooded object or arm. Typical fan splashes disposition can indicate on the place of the corps finding of bleeding or blooded object.
Sparks and flows of blood
Drops are the blots, which are generated attached to vertical blood fall with their own weight on horizontal surface from small height. Have a form of steep. Dimensions and peculiarities of these blots depend on fall height. Round form with diameter less then 1 cm and equal edges witness about fall height 10-15 cm, with diameter 1-1,5 cm and something jagged edges indicate the height of 30-50 cm, blots with expressed jagged edges, radial shoots and diameter 1,5-2 cm arise in the case of falling from height 60-80 cm. If fall height is 1,5-2 meters and more, blots diameter can be near 2,5 cm, edges radiant, arise a secondary splashing: blood spills, forming round shallow additional drops with form of points, stripes, rays. When the fall height is considerably great, the blots loose their round shape. Drops of the blood, which fall during man’s movement (running or going) form the blots with form of note of exclamation, their sharp ends indicate direction of movement. If the object moves very fast, then drops break into sparks when fall. Drops of the blood witness about bleeding, shift of injured man or transference of the corpse. These traces help to define direction of motion, it tempo, stops places.
Flows of blood – traces of blood, which flowed, such blots, which form, when blood flow down on sloping or vertical surface with it own weight. They form blood tracks, a little wider in top part, then in lower one, where blood amass and gets dry in appearance of the pin bulge. This give a possibility to judge about flow direction. According it direction one can also define regulation of injured man in the moment of trauma, sometimes –wounds sequence, approximate amount of blood, that flowed away, change of body or object regulation in the moment of flow formation.
Puddles – are the blots of various form and size on horizontal surfaces, which do not absorb or little absorb moisture. They arise as a result of effluence of considerable amount of blood from wounds and spread it around.
If blood accumulates gradually from insignificant height, then puddle will have clear edges without splashing traces. Flowing down blood from some height may be spilling, from puddle edges move away radiant offshoots, around there are some amount of splashes. On rate setting of blood package and amount of whey, that divided, one can judge about remoteness of the bleeding. Puddle can indicate the place of injuring or death, amount of lost blood, sometimes – regulation of injured person. Dry remainder of 1 liter of blood is 211 grams.
Blots of the blood have got an indeterminate form, that arise as a result of touch of bleeding or blooded object to some other object. Such blood blots arise, for example, on rag, paper or towel from wipe hands muddy with blood or other objects. Sometimes they have an oblong, broken form. It’s difficult to define a source of blood blots beginning or origin using their form. However, sometimes can make supposition about that, are the blots from wipe of some blooded article or implement.
Blood impresses – blots, which are arised as a result of static contact between some surface and blooded object. Frequently these traces reflect the shape, size, relief of this object. On the scene of death most frequently meet impresses of fingers, palms, footwear sole, other objects. They can contribute to establish person of a criminal or reflected object.
Invisible or hide traces of blood on the scene of death may be expressed by means of luminol. Workplaces, blots shade and traces, looks like blood, work up by luminol solution from pulverizer. Blood blots momentary independently light with sky-blue color as a result of energy, which exudes during chemical reaction between blood ferments and components of solution. Fresh blood lights weak, dried up – much better. This method does not destroy the blood and gives a possibility to carry out the next research.
Traces of the sperm in the scene of death one should search on different objects, clothes in case of sexual crimes. On absorptive clothes dried up sperm blots have an indeterminate form, sinuous edges, a little hard, remind starched allotments. On dark clothes sperm blots are whitish, on light one – grayish with yellow hue. Sometimes on blot surfaces one can see gray-white scales. On unabsorptive clothes or objects sperm traces are like shining formation of grayish-white color, sometimes with yellowish hue.
Traces of the saliva one can found on cigarette ends, cigarettes, envelopes valves, postage-stumps, gags, edges of crockeries, which used for drinking, on food, gobs. Saliva contains ABO antigens, so it research in judicially-medical laboratory gives a possibility , for example, to define blood group of the smoker, to solve question, what person omitted cigarette ends, to confirm using of rag, towel, hand kerchief or other object like a gag, to determine author of anonymous letters etc. Cigarette ends have to be collected by pincers, not to omit on them antigens of stranger group as a result of sweat excretion of person, which withdrawal material evidences. Each cigarette end place into separate envelope or packet.
Traces of the sweat express on head-dresses, crests, clothes, on internal footwear surfaces. Expressing of sweat and determination antigens of ABO group in it helps to refer investigated garments to concrete subject and also to settlement other questions, for example, to determine presence of some person in the scene of death.
Traces of the faeces and urine ordinary find in tracks, where a crime happened. In that case arise a question: do they belong to the criminal or no? Faeces gives a possibility to define, what food and what time before crime used the criminal. Using colour of faeces sometimes judged about some diseases (colourless faeces –in case of icterus, tinted by blood – dysentery etc.). Using allocation of faeces and urine one can defined sex of the person, which omitted traces.
Hair in the scene of death can be expressed on different trauma implements, in the corpse hands, on clothes or body of suspected and victims, on combs, on carriers etc. It withdrawal and research in laboratory, that gives a possibility to settle a row of important questions. For hair search is necessary good illumination, using of magnifier with wide eyeshot. Similar to hair objects
take by pincers with elastic tips, not to damage them. Withdrawal objects place into separate paper packets.
Traces of dragging of the man are continuous or broken disturbances, their properties and peculiarities depends on description of surfaces, on which dragged the body: on soft surface they are pressed, on hard one – superficial. Traces of dragging meet in cases of transport traumas, murders, when a criminal caot alone dislocate dead body to some place by other method. Along the stripes one can find blood, elements of the corpse clothes, objects, which fall out from pockets of the corpse or of the criminal etc. Blots of blood define along the stripe from one or both sides. Using area of blood splashes or flows one can define area of dragging, and using their sizes and peculiarities – deduce, from what height the blood fall down. Near the stripe can be found traces of legs, criminal’s footwear. Area of motion can be defined also using tat fact, that herbage stem or other vegetation bent or broken to that side, where the corpse heaved up. Spying dragging stripe motion one can find a place, where from attracted the body.
Traces of objects, that used to motor vehicles: bicycle traces, carriage, cartful, sledges, motor-cycle, car, tractor, other means of transport, stick and impresses, skis etc. in case of crush have to be thoroughly described, photographed, if it’s possible – withdrawal their gipseous moulds.
Searching and describing various traces in the scene of death, doctor or judicially-medical expert must take care about that, to save them from damaging or destroying. An the same time it is impossible to omit the own traces in the scene of death.
So, examination of the scene of death and the corpse in the place of its finding presents by multi-faced primeval complicate investigator action. Correcting and skilled inspection with using of all judicial norms is very important for successful investigation of the crimes, specifically against man lives.
FORENSIC EXAMINATION OF BIOLOGICAL FLUIDS STAINS AND OTHER MATERIALS
In the investigation of crimes, such as murder, dacoit etc, the examination of biological materials plays an important, role in connecting the criminal with the crime video. Such biological specimens may be in the form of body fluids or stains, or other material, as for example, blood; semen, saliva, urine, milk, and hair. These are briefly discussed here with special reference to their medicolegal applications.
DIFFERENT BLOOD GROUP SYSTEMS
There are several quite distinct and unrelated types of deference between the bloods of different individuals. These are due to (1) the red cell antigens located in cell walls and responsible for ABO, MN, Rh, and other blood groups (2) blood proteins such as haptoglobins, Gc, Gm and Inv immunoglobulin types and various varieties of haemoglobin, and (3) polymorphic, mostly present in the red cells. These differences help in grouping and subgrouping of blood. The secretor status (vide infra) allows blood group determination in the absence of bloodstains or blood.
An integral part of the ABO system is the secretory system. Approximately 80 per cent of the population secrete ABO blood group substances in most of the cells and fluids of the body. These individuals are known as secretors. The rest no blood approximately 20 per cent, who secrete very little or no blood secretors group substances, are known as non-secretors. All secretors also secrete a substance called ‘FT substance. Accordingly, an A blood group person will secrete in his body cells and fluids group A substance and H substance; B blood group person group B substances and H substance; and O blood group person only H substances. The secretor system is determined by two alleles Se and se, which occupy one locus on a pair of chromosomes. The Se gene is dominant to the se. The resulting genotypes are Sese, Sese and sese. The presence of the Se gene allows the blood group substances present in the cells and fluids of the body to be acted upon by a series of transferases, which cause the substances o become water-soluble. ASH group specific substances are found in high concentration in saliva, semen, and vaginal secretion an gastric juice, and in rather low concentration in sweat, tears and urine. The presence of blood group substance in these secretions can be of great value in medicolegal studies. The substance is stable and allows another method of blood grouping when bloodstains are not available. As for example, it is possible to determine the blood group of an individual from an examination of these secretions from saliva on cigarette end or from a seminal stain, and such examination may provide vital clues in the solution of a crime.
The Rh antigens are often responsible for the so-called haemolytic disease of the newborn, as well as for unexpected, untoward reaction in cases where transfusion of compatible ABO blood has been carried out. Great multiplicity of Rh antigen and relatively simple mechanism of their inheritance decide the usefulness of the Rh blood group system in cases of disputed paternity.
Medicolegal Aspects
The application of blood group determination to medicolegal problems is resorted to for the following purposes: (1) it is a means to ascertain the possible source of blood stains in circumstances of murder, wounding, rape or vehicular accident, (2) It is of considerable value in resolving disputes of paternity, maternity, and in inheritance claims, (3) It is by far the best, defined inherited human characteristic and therefore the most useful in problems of identity. (4) The forensic pathologist more usually the clinical pathologist may have to investigate death believed to have been due to an incompatible blood transfusion.
BLOOD STAINS
The points that are usually required to be determined regarding stains are: (1) the nature of the slain (2) if due to blood, the species (human or animal) it has come from, and (3) if human: the group to which it belongs’. In some cases, it is also necessary to determine the character and causation 01 stain. To determine these facts, the following examinations are carried out, viz, physical, chemical, physicochemical, microscopic, spectroscopic, immunology, and enzymological.
PHYSICAL EXAMINATION
Visit to the scene of crime providlls valuable clues. The examination should include (a) clothing (b) size, shape, and direction of blood spots (c) character (d) age, and (e) tile body.
Scene of Crime
In the case of stains, it is the routine practice of the police to take photographs of the scene of crime. Black and white photographs of bloodstains are not of much value since walls from which bloodstains are scraped give the same appearance as stains. Colored photographs, are therefore preferable may be taken when facilities permit.
Clothing: If victim was asleep in supine position when wounded, blood would flow towards the back and stain would be found at the appropriate places on the clothes. As for example if his throat is cut, his shirt collar and clothing at the wounded blood stained; while, if the victim was standing when well as all blood will fall vertically downwards on the clothes as the body.
If bloodstains are found on the underwear or petticoat of the victim they are suggestive of injuries to the genital organs or a sexual assault.
If the clothes are soaked with blood it would mean that the victim bled profusely and lived for some time after the injury.
Size shape and direction of blood spots: When blood fails .51 e, downwards on to a flat surface the stains flattens out in the form a circle if the height does not exceed a few centimetres. With the increase in height, the circle shows projections round the circumference, the number of projections being directly proportional to height. Spurting (arterial) blood striking the surface obliquely produces elongated stains
resembling exclamation marks, the sharp end of the mark indicating the direction of the spurt. The more oblique the fall, the more elongated is the stain. Thus, the size and shape of the ‘stain indicate the height from which blood has fallen and the direction of the fall of blood.
A trail of bloodstains indicates that the victim received his injuries at some distance from the place at which the body was found. It may suggest attempted running or sometimes attempted suicide. A person may attempt to cut his throat, walk for some distance and then jump into a well. In such circumstances, a trail of blood is usually found.
Character: Sometimes, it is possible to determine if blood came from (a) living or dead body (b) artery or vein (c) victim or assailant, and (d) infant or adult. Living or dead body: Blood, which has effused during the life can be peeled in scales on drying on account of the presence of fibrin. Blood, which has flowed after death tends to break up into powder after drying.
Artery or vein: blood coming from the arteries of a living person will be scattered In spurts over surfaces upon which it has fallen. Venous blood comes out in the form of oozing or a continuous stream, which will produce a pool if the victim is at rest and separate widespread drops if he is ambulant. It should however be remembered that a considerable pool of blood may collect under a dead body and it could be postmortem iature due to opening a large blood vessel, as for example, after stab injuries on a depended part. Generally, in most bleeding wounds, blood is poured out simultaneously from arteries and veins.
Victim or assailant: It is generally difficult to determine whether bloodstains belong to the victim or an assailant.
Stains on the inner side of the garments usually belong to the victim while those on the outer side may have come from the victim or assailant. Stains on dark clothes if not properly visible may be revealed in detail by photographing in ultraviolet infrared light.
Bloodstains may bear marks of finger or footprints. These may help to connect the accused with the crime. Sometimes there may be some blood disease, eg, leukaemia, filariasis either in the victim or the assailant. This may provide valuable information. Traces of blood may be found underneath the finger nails of the victim as a result of struggle or of the assailant in case of throttling. Such stains caow be typed and grouped without any ambiguity. The specimen can be collected either by nail clippings, and if such mutilation is resisted, by nail scrapings with the help of cuticle sticks or the blunt end of a tooth prick.
Infant or adult: In foetuses and premature babies as well as in children born with some blood disease, a number of ‘red blood cells are nucleated. In normal newborn children, the nucleated red blood cells are observed only occasionally. In general, the red blood cells of young babies exhibit more fragility, the haemoglobin of the foetal type is present up to about six months, and the blood when shed forms a thin and soft coagulum. In the adult, the red blood cells are non-nucleated, their fragility is within certain limits, haemoglobin is of the adult type, and the blood when shed forms a thick and firm coagulum.
Age: One should always note when visiting the scene of crime whether any efiused blood has coagulated, the extent of coagulation, and also whether spots of blood are dry or not. If blood has not clotted or dried, it indicates recent bleeding. It takes, half an hour for a drop of blood to dry in ordinary circumstances. The appearance of clotted blood is very typical and if a fabric has been soaked in blood, it becomes stiffened.
Recent stains on white cloth are at first red. After a variable interval, due to conversion of haemoglobin into methaemoglobin and haematin, the colour gradually changes to reddish brown within about 24 hours, dark brown or even black within the days and remains so for several years, depending on the thickness of the stain and the conditions to which it has been exposed. On some dark fabrics, the stains are difficult to locate washed and may easily escape an examination by the naked eye; washed stains on while fabrics look yellowish and they are also very hard to detect. It is generally helpful to use ultraviolet and infrared light to detect such stains. On many metallic articles, bloodstains as dark staining spots or smears, and when desiccated, show fissure and cracks. Such stains when recent are more soluble distilled water or normal saline than old ones in which, haemoglobin gradually changes to methamoglobin and finally to insoluble haematin. Thus, the most that can be said regarding the age of a stain is that it is recent, or not very recent, and even that opinion sometimes cannot be given.
The body: A person may collapse after receiving an injury, multiple stab wounds. A large pool of blood may be found. It indicates that the victim was alive when wounded and lived for sometime after the injury.
When there are number of wounds on the body but the amount of blood is scant, it would mean that either the blood has been wiped out in which case smears are found or that the body has been moved from elsewhere. Both situations are suggestive of murder.
After physical examination is carried out at the crime scene, the various exhibits, eg, clothes, stained weapons, etc, should be forwarded to the forensic science laboratory (FSL), properly preserved, without any delay.
DETECTION OF BLOOD IN STAINS
Whilst the appearance of a typical stain leaves no doubt as to its nature, some stains especially old ones, due to red paint, fruit juice, banana leaf juice, vegetable dyes, rust, faeces, pan, red lead etc, simulate blood stains. Such stains must be differentiated from bloodstains: Two screening tests may be employed: (1) ammonia turns vegetable stains and fruit stains green, whilst nitric acid turns aniline dyes yellow, blood being unchanged (2) an alkaline solution of aminophthalic acid hydrazide is mixed with hydrogen peroxide and sprayed on the suspected area with an atomizer. The area is rendered luminescent if the stain is due to blood. Even when stains are profuse and appear to be certainly due to blood, it is advisable to have a scientific confirmation of this fact.
Chemical examination
The most commonly employed chemical tests to determine the presence of blood. In the stain are: (1) the benzidine test, and Kastle-Meyer test. Occasionally, malchite green test and toluidine blue test are also used.
Physicochemical examination
The most commonly employed physiochemical tests to confirm if necessary, the presence of blood in the stain is: (1) thin layer chromatography (TLC) and (2) electrophoresis.
Microscopic (microchemical) examination
By microscopic examination of the stain, we may obtain information about the presence of haemoglobin, the colouring matter of blood. For this purpose, two chemical tests are employed, viz (1) Takayama’s haemochromogen crystal test and (2) the haemin crystal test (Teichmann’s test). These are also known as microcrystal tests. It should be remembered that it is not possible to detect red blood cells in stains unless the stain is very fresh.
Material for the microscopic examination of red blood cells is obtained by soaking the stain iormal saline or preferably Vibert’s fluid in a watch glass. Vlbert’s fluid is prepared by mixing two grams of sodium chloride and one half gram of mercuric chloride in 100 ml of distilled water.
DETECTION OF SPECIES ORIGIN
Hie tests discussed so far prove that the stain is that of blood. The next important step is to determine if the blood under examination is that of a human being or is derived from any other source (animal) for three reasons: (1) Sometimes, a plea is put forward that the blood stain has been derived form animal blood especially when ‘the accused is a butcher or a hunter (2) some animals possess blood group antigens (substances) similar 10 those found in human beings: it is therefore necessary to rule out any contamination from such source while interpreting blood group results so as to conclude that the blood under examination comes from a human being only, and (3) in cases of suspected illegal shooting of certain prohibited species of animals, such as peacock, sambar, neelgai, tiger, etc, it is imperative to determine the exact species of animal from which blood has been derived. The following immunological and enzymological methods are used for this purpose.
Immunological methods
The commonly employed immunological methods are: (1) precipitin test (2) haemagglutination-inhibition test, and (3) latex test.
Precipitin test: This test depends upon the fact that when a foreign protein like human blood serum is injected into an animal certain specific antibodies known as precipitins are formed in that animal’s blood which precipitate that specific foreign protein. The specific foreign protein, which causes the production of precipitins is known as precipitinogen. For ex.ample, if a rabbit fowl or any other suitable animal is injected with repeated small doses of human serum, either subcutaneously, intramuscularly intravenvenously or intraperitoneally, its serum after a certain time will be found to contain the anitbodies-precipitns. This serum is separated and used for preciptitin test of the material suspected to contain human blood.
It will be found to cause a precipitate when mixed with human blood serum even in the minutest amounts; in fact, it will cause recipitate when mixed with blood or albuminous material from a different species of animal. The test will therefore demonstrate the presence of protein substances obtained from of human body. The origin of skin, flesh, bone, or even secretions such as saliva, milk and semen can be established by this test.
Using the following three techniques performs the test: (a) test tube {b) gel diffusion, and (c) cross-over electrophoresis (COE).
SEMEN
Semen is a fluid secretion containing cellular elements. The fluid portion is formed in the seminal vesicles and prostate and contain a high concentration of choline and lecithin secreted by the semina.! vesicles and a high concentration of acid phosphataseand spermine secreted by the prostate. The cellular elements consist of spermatozoa and epithelial cells formed by the testes.
Semen is a thick, yellowish white, glairy, opalescent secretion having acharacterislic odour known as seminal odour. The normal quantity of semen in one ejaculate varies from 2 to 5 ml. In a healthy adult male, the total number of spermatozoa in one ejaculate is about 200 to 500 millions (one hundred million per ml) of. which at least 80 per cent are motile. The secretion is slightly alkaline in reaction. Liquefaction of the secretion occurs within a short period due to prostatic fibrinolysin. The question of detecting seminal stains arises in charges of rape, sodomy, and bestiality. These stains are usually found on.the clothing but may be found on the body of either victim or the accused, on the bed clothes or where the offence is committed. These are sometimes found mixed with blood, mucus, pus or faeces, especially on the articles of clothes.
The examination of seminal stains may be carried out by four methods, viz, physical, chemical, microscopic, and electrophoretic. The material for examination is collected as follows:
When seminal stains are found on clothing, the portion bearing the stain is cut dried in the shade to prevent putrefaction, and carefully preserved. Seminal matter may be found on or about pubic hair and if the hair are matted together, a portion must be cut off and kept for examination. To demonstrate the presence the semen in vagina, swabs and smears are prepared as outlined under topic “Collection and Preservation of Biological Materials”. Dried or drying seminal, fluid on the thighs and perineum is collected on a piece of moistened cloth and dried.
Dry stains on smooth surfaces can also be gently scraped with a clean, blunt scalpel into a glass container.
Physical ‘Examination
Garments submitted for medicolegal laboratory examination are often dirty and may contain a variety of stains ranging in colour from red, brown or yellow to a faint almost imperceptible greyish colour, Those of reddish colour are commonly composed of blood; of a yellowish colour, from vaginal discharge or urine;: of a brownish colour, from faeces: while those of a greyish appearance may be due to semen. To narrow, the line of investigation, a preliminary examination under filtered ultraviolet light can be made, when stains such as those composed of urine, leucorrhoeal discharge and seminal fluid will show a bright fluorescence, The fluorescence of seminal stains is of a bluish white colour and stains reacting in this manner should first be selected for further examination.
Chemical Examination
The tests most commonly performed for this purpose are: (1) Acid phosphatase test (2)
Acid phosphatase test: This test is, of value in the investigation of cases of rape, sodomy and bestiality as a high concentration of acid phosphatase is found only in the semen of human beings and monkeys, The test is a quantitative one and is usually carried out by measuring fixed quantities, eg, one square centimeter of stained material, and estimating the amount of acid phosphatase present. This test is specially valuable because old stains also give a positive reaction, and the seminal origin of the stains can be determined even in the absence of sperms. Inhibition of acid phosphatase activity of semen by I-tartaric acid was till recenUy taken as a reliable proof.of the presence: however, it has now been shown to be allowing the discovery of similar reaction given by vaginal secretion. Nonetheless, as a screening it is quite valuable.
Microscopic Examination
This examination is meant to demonstrate the presence of spermatozoa from/fresh unstained smears and those which have been fixed and stained. Care must be taken not to mistake trichomonas vaginalis for spermatozoa. The sperms generally remain motile in the vaginal canal for about two to three hours: and non-motile forms are detectable for about 24 hoursd The sperms may remain alive in the uterine cavity for 3-5 days. Non-motile forms may be found in the female genital trac about 3 weeks to 3 months after death.
The seminal stains when presented for examination are usually a dried condition, and before their constituents can be examined microscopically, they must be moistened in order to obtain an extract. Excellent results are obtained by microscopic examination of scrapings of a stain, taken from the surface, on a slide, following the addition of a drop or two of a 0.3 per cent solution of glacial acetic acid in distmed water. In the majority of cases, particularly when the stains are fairly thick and not of recent origin this method is preferable to the soaking method. In the later method, a portion of the cloth bearing the stain is cut, and soaked in a small quantity ‘of acidulated water. Soaking is continued from half an hour to four hours or more depending on the age of the stain and the nature of the fabric. By means of a pair of a clean forceps, the fabric is removed from the solution and dabbed gently several times on a clean side. The smear is allowed to dry, then lixed by gentle heat, and stained by haematoxylin and eosin. It should be examined under high power objective. Human spermatozoa are about 50 microns long, and consists of a head measuring 5 microns in length and 3 microns in breadth, a short body, and a long filamentous tail. The head is ovoid and flattened when viewed in front, and about one-third the size of a human red blood corpuscle, and is pear-shaped when viewed in profile. In the stained specimen, the hind part of the head of the sperm acquires a deep blue tint whilst the front and middle of the head and its tail are stained deep red.
In seminal stains, in addition to mature spermatozoa, there may be sperm cells in different stages of development; mass of debris and cells from the prostate. Certain yeast like fungi and varieties of monilia resembling spermatozoa are also seen. Under the microscope, it is not difficlt to recognize a spermatozoon when it is entire because of its large and obvious head its neck and filamentous tail. If only disconnected heads and tails are found, as is sometimes the case in stains that have been roughly handled, a definite opinion as to the presence of spermatozoa can be given only by an expert. The disconnected head may be confused with numerous microorganisms like yeast, trichomonas vaginalis, and cellular material of vaginal or other origin. Therefore, as a rule, a complete spermatozoon is necessary before a positive result can be given on routine microscopic examination. However the presence of a Y chromosome can identify the disconnected head of a spermatozoon under fluorescent microscope (vide infra). The discovery of spermatozoa in stains is not always an easy matter for the obstructive elements are many. The important responsible factors are the character of the fabric, the age of the stain; and the condition to which It has been exposed before reaching the laboratory for examination. The failure to find complete spermatozoa or separate heads and tails in a stain eextract does not exclude the possibility of the stain being a seminal one. The fabric may have been washed or the sperms may have been filtered to leave only the fluid fraction on the fabric or the male may be azoospermia very old, or undergone vasectomy more than six months ago.
Recently, fluorescence microscopy is used for the detection of spermatozoa. This method has the advantage over routine microscopic examination in that the interference from microorganisms, other cellular material, and fibers from the garment call be avoided. It is based on the principle that the Y chromosome is fluorescent to quinacrine. With this method it is possible to detect both intact spermatozoa as well as the disconnected heads which often show the presence of fluorescent Y bodies in them.
SALIVA
The identification of saliva on cigarette ends and on clothes is important in crime investigation. A sample of saliva may be obtained from both the suspect as well as the victim in crimes such as sexual offences to determine the secretor status. To collect a sample of saliva for analysis, the mouth should be thoroughly rinsed with water five minutes before collecting the sample. To stimulate flow of saliva, the subject should chew a small square of paraffin wax (not chewing gum). Saliva can be detected by measuring the amylase activity by the starch -iodine test and/or Phadebas test. Some individuals produce saliva with little or no amylase activity. These tests therefore need to be supplemented by other tests, such as examination of buccal epithelial cells under microscope.
The precipitin test is used to determine species origin and the absorption-elution method for blood group substances. For ABO grouping authors suggest the use of absorption-inhibition , rptlon-elution methods simultaneously together with suitable dilutions in both the methods to eliminate nonspecific reaction.
URINE
Examination of urine and its stains may be necessary in cases of murder and sexual assault.
Urine stains on fabric may appear pale yellow or may have no naked eye appearance of their presence. These give fluorescence when examined under ultraviolet light. A concentrated extract of the stam may give a characteristic smell due to ammonia evolved by bacterial degradation of urea.
The chemical tests to detect urine from the stains depend on the presence of urea and creatinine in urine. Urastrat method or p-dimethyl-aminocinnamaldehyde is used to detect the former and TLC for the latter. The precipitin test can be attempted, to determine the species origin.
HAIR
The examination of hair is of importance in indication. The examination of hairs or fibers found at the crime, on weapons, clothes, etc, is however of much greater importance in the general investigation of crime. Specimens of hair removed from various parts of the motor car are occasionally sent by authorities for examination and comparison with hair on the head of deceased persons who have been the victims of road accident. In sexual offences, especially in rape and bestiality, an examination of hairs frequently becomes important. In chronic poisoning by metals, an examination of hair provides essential data for the investigation of hair is a task for the expert.
Examination
The points to be considered in the examination of the hair are: (1) the nature that is if the material is hair or some other fiber (2) if it is hair, its source, whether human or animal (3) if human, the race, age, sex, situation, and special features for identification (4) video evidence in relation to suspected crime, and (5) in case of dead bodies, the times since death, if possible.
NOTES, USEFULL FOR DeterminATION OF Time SINCE Death
The following material was edited by Jeff Kercheval and obtained from:
VICAP International Symposium
AAFS New York Meeting New York, NY, February 17 – 22, 1997 material presented by: Patricia J. McFeeley, M.D.
Chief Medical Investigator State of New Mexico Albuquerque, New Mexico Armed Forces Institute of Patholog George
“Sptiz and Fisher’s Medicolegal Investigation of Death-Guidelines for the Application of
Pathology to Crime Investigation, 3rd Edition” Edited by:
The crime scene investigator should be familiar with the following concepts for effective evaluation of a crime scene involving deceased victims.
EARLY STAGES OF DECOMPOSITION:
RIGOR MORTIS:
Muscular relaxation immediately after death is followed by the gradual onset of rigidity without shortening of the muscle. This is caused by the conversion of glycogen into lactic acid. The conversion of glycogen into lactic acid is attributed to metabolization of muscle for a short time after somatic death, or from products built up during the death event. As the pH decreases, there is aphysical change in the muscle protoplasm. There is a cross-linking of actin and myosin by the presence of excess lactic acid.
Perception of rigor is more rapid in the smaller muscles, however, all muscles are affected at a similar rate. The rigor is more evident in the short, smaller muscles earlier than in the longer, larger muscles.
Because this is a chemical process, heat accelerates and cold decelerated the process. Acidosis, uremia or other medical conditions promoting a lowered pH accelerate the process. Rigor is typically quantitated by “mild”, “early”, “moderate”, “and “complete” as a descriptive statement of degree of change. This is totally subjective and two observers may have different interpretations. Usually, perceived stiffness in motion of a joint is “mild”, difficulty requiring force to move a joint is “moderate”, and having to use great force is “complete” rigor.
Once the physical change of the muscle is forced, that degree of change will not reoccur, so that if someone has broken the rigor, it will not reform to completion. If only partial rigor is present, some rigor will continue to form.
Some conditions which affect rigor mortis include: temperature illness activity before death physical conditions where the body are found
MECHANISM ONSET MANIFESTED MAXIMUM DISAPPEARS
Physical change Immediate 1 – 6 hours 6 – 24 hours 12 – 36 hours
LIVOR MORTIS:
Livor mortis is the settling of blood to the dependant parts of the body. When cardiac activity stops, the hydrostatic pressure of the liquid blood causes it to settle to the lowest points within the body (depending on body position) and distend the dependant capillary bed. The color of the dependant part will depend on skin pigmentation and any additional compounds which may be present within the blood (i.e. carbon monoxide, etc.). The areas where the blood has settled will generally be dark blue or purple in color. Livor begins at or very soon after death since it is a function of cardiac activity. However, stasis can occur to some extent in shock and some degree can be present even while the person is technically alive.
Settling Immediate 2 – 4 hours 8 – 12 hours Livor will not usually develop where there is pressure from clothing or objects. Therefore, important information regarding whether a victim was clothed for a period of time after death or if body position was changed can be gained from a careful inspection of the livor’s distribution. Generally, time can best be supported from observation of livor and comparison with the accelerating or decelerating factors affecting that particular scene.
TARDEAU’S SPOTS/PETECHIAL HEMORRHAGES:
Accumulated blood which has settled in an area may cause capillaries in a small area to rupture so that circular or rounded areas of skin hemorrhage occur. These areas may range from pinpoint in size to 4 –
ALGOR MORTIS:
Algor mortis refers to cooling of the body. Postmortem body temperature declines progressively until it reaches the ambient temperature. The metabolism of the body generates heat which is regulated to a narrow range. If the body cools at a uniform rate, then the rate of temperature decrease could be used to accurately determine the time of death. However, the body temperature is a narrow range, not a fixed temperature. Activity, illness, decomposition, infection and absorption of heat can maintain or raise body temperature after death. The body cools by radiation (transfer of heat to the surrounding air by infrared rays), convection (transfer of heat through moving air currents) and conduction (transfer of heat by direct contact with another object). Therefore, many factors may influence the rate of heat loss. Careful consideration of the scene, clothing, victim size, activity and physical factors must be considered in interpreting cooling rate. The Glaister equation is one formula used for determining the approximate time period since death based on body temperature. 98.4% – measured rectal temperature = approximate hours since death 1.5
Temperature has to be considered in light of all the scene data. For example, a deceased person who has been in a closed car all day with the sun shining on the car who is observed at night could not be expected to cool in a regular manner. In fact, an individual in this situation may well have a body temperature above “normal”. Several individuals who have studied the effects of body cooling suggest that the rate is not constant, but rather more heat is lost during the first few hours, then as the body begins to reach ambient temperature, the rate of heat loss slows.
DESCRIPTION EYES OPEN EYES CLOSED
Corneal film minutes several hours Scleral discoloration “tachy noir” minutes to several hours Corneal cloudiness 2 hours or less 12 – 24 hours Corneal opacity 3rd post-mortem day Exophthalmos (Bulging) with gas formation with gas formation Endophthalmos (Retraction) with advanced decomposition with advanced decomposition
FOOD IN STOMACH: (This information can be gained at autopsy)
SIZE OF MEAL TIME IN STOMACH (starts to empty within 10 minutes)
Light 1 _ – 2 hours
Medium 3 – 4 hours
Heavy 4 – 6 hours
Variations:
Liquid is digested faster than semi-solid food, which is digested fasted than solid food.
Emotional state may also influence the rate of stomach emptying. Psychogenic pylorspasm prevents stomach emptying for several hours. Hyper motility may cause diarrhea.
VITREOUS POTASSIUM:
The body maintains an increased concentration of potassium in the intracellular fluid. This increase is 2- to 40 times the concentration of potassium within the plasma. This high concentration requires a balance between the electrical charges inside and outside the cell membrane and is maintained in this relatively high concentration be active metabolic forces that “pump” the electrolytes selectively across the membrane. A return to equilibrium occurs after death at a steady rate because the pumping mechanism is no longer active and the cell wall becomes a semi-permeable membrane that allows the potassium to leak through the membrane to approach equilibrium. The leak is at a steady rate because of the mechanical limits of the membrane. This steady rate provides a built-in clock that allows a projection back to the time of death. An ideal sample, protected from most trauma is the vitreous fluid of the eye. Calculations are most accurate when samples are obtained within 12 hours after death.
One formula developed for estimating the time of death based on a uniform potassium leak rate of 0.14 mEq/L/hr. is: (7.14 x K+ concentration) – 39.1 = hours since death
Soon after this data was published the formula was found to be inapplicable for some locations and/or situations. It is suggested that your medical examiner determine the rate for your specific location.
Postmortem Tissue Changes:
Decomposition: Involves two major components. These components are:
Autolysis: The process by which digestive enzymes within the body cells break down carbohydrates and proteins. Autolysis usually starts in the pancreas.
Putrefaction: The major component of decomposition which is due to bacterial activity.
Characteristics of putrefaction include:
1) Gas formation and bloating
2) Green discoloration of abdomen
3) Marbling along blood vessels-a brown black discoloration in blood vessels caused
by hydrogen sulfide gas
4) Blisters and skin slippage
5) Loss of hair and nails
Mummification: Drying of the body or its parts with “leather-like” changes. Mummification is characteristically seen on the tips of the fingers and nose. It can occur in as little as 1 – 2 days.
Skeletonization: Characterized by removal of soft tissue. Occurs largely as a result of insects and animals.
Adipocere: Formation of a waxy substance due to the hydrogenation of body fat. A moist, anaerobic environment is required for the formation of adipocere.
EXTENSIVELY DECOMPOSED/SKELETONIZED REMAINS:
Should be treated as any other scene involving careful examination and documentation of the scene, collection of evidence, etc.
The best approach is to plan ahead. Another day at this stage will probably not change the scene significantly, but could make the final conclusions better.
Use the services of a forensic anthropologist if possible. The weathering of bones depends considerably on:
Buried or not buried
Climate
Moisture
Elevation
Terrain
Protection Insect/animal/human intervention Check weather bureaus for rainfall, temperatures, etc.
INSECT INFESTATION (FAUNA):
INSECT INFESTATION MINIMUM POSTMORTEM INTERVAL
Body lice Outlive host by 3 – 6 days Blow flies May deposit ova before or at death –larva (maggot) – hatch within 18 – 24 hrs. -pupae/casings + week
Insects/Arthropods In temperatures greater that 40o F. –Highly dependant of locale, temperature, season
-Collect samples in preservative (85% alcohol) and take to an entomologist -Collect soil sample from around body (within
PLANT LIFE (FLORA):
1) Grass/plants beneath an object wilt, turn yellow or brown and dies. The rate depends on type of plant, season, climate, etc.
2) Seasonal plants or remnants may help indicate a range of time.
3) Collect dead and drying grasses, twigs, flowers, etc. and take to a local botanist.
METHODS FOR THE ESTIMATION OF TIME OF DEATH…SUMMARY
Rate: Method: Estimation by evaluating the presence/absence of an indicator in a deceased in conjunction with the known behavior of such indicators.
Concurrence Method: Estimation by evaluating events which happen at or near the time of death, or offer information suggesting a time period for the death event.
METHOD TYPE INDICATOR
Rate Method Rate of drying or discoloration of blood pools
Rate Method Rigor Mortis
Rate Method Livor Mortis
Rate Method Algor Mortis
Rate Method Decomposition
Rate Method Flora (plants) around body
Rate Method Fauna (insects) around body
Concurrence Method Time of last known meal
Concurrence Method Stopping of watch (due to trauma/damage)
EVIDENCE FOR ESTIMATION OF TIME OF DEATH:
1) Corporal Evidence: In the body
2) Environmental & Associated Evidence: In the vicinity and general surroundings
3) Anamnestic Evidence: Based on the decedent’s ordinary habits and daily activities
CORPORAL EVIDENCE ENVIRONMENTAL & ASSOCIATED EVIDENCE
ANAMNESTIC EVIDENCE
Stage of decomposition of internal organs vs. exterior of body Uncollected mail/newspapers Usual activities soot in airway (fire/smoke inhalation).
Lights on or off Walking & sleeping patterns Evidence if medical conditions Alarm clock set Eating habits, times, types of food.
Alcohol/drug levels Food on stove/in refrigerator Appointments Beard/nails/hair Type of clothing day/night indoors/outdoors seasonal condition of clothing (mold/leached dyes, etc. Answered/unanswered correspondences Presence of sale slips or receipts in clothing Animals/pets in house
IDENTIFICATION OF THE DEAD
Primary Physical Characteristics (characteristics which are very difficult for a person to change during life.
Some of these characteristics will appear to alter post mortem):
• Sex – usually obvious.
• Age – external appearances, internal degenerative disease, bones, joints.
• Height or stature – N.B. height of corpse differs from that in life by up to 2-
• Weight – corpse often appears of different build to that in life
• Race
• DNA (unique to every individual. Considered in detail in the lecture notes on Genetics & Parentage Testing)
Secondary Physical Characteristics (characteristics which can change during life, either deliberately by deceased or as a result of medical/dental interference.
Some of these characteristics will appear to alter post mortem):
• Skin colour (alters post mortem)
• Eyes – more useful in caucasians thaegroid & mongoloid races. Colour can alter PM
• Teeth – very resistant and bear much useful information.
• Hair – colour, style, length, beard/moustache.
• Scars – surgical procedures and prostheses.
• Tattooing – seen even if the body is putrefied.
• Fingerprints
• External peculiarities – circumcision, moles, warts.
• Deformities
• Clothing and other objects
• Jewellery
• Cosmetics
DNA is unique to every individual (except monozygous (identical) twins. DNA comparisons allow for definitive identification of an individual. The biology of DNA and the procedures for analysis are considered in detail in the lecture notes on Genetics & Parentage Testing. This is forensically useful in the living (strong evidence of involvement in assault, rape, disputed paternity) and the dead (DNA survives in bone for many years, comparison of DNA with family members)
IDENTITY OF DECOMPOSED OR SKELETAL REMAINS
Are the remains human or animal? (butchers offal, skeletal remains of dead pets etc. may be found in unlikely places) If the remains are only bones:
1. Are they really bones? (wood, stones)
2. Are they human?
3. How many bodies?
4. How long dead? – recent or ancient (e.g. construction or digging at an old burial site)
5. Cause of death?
6. Sex?
7. Age?
8. Race?
9. Stature?
Try out an exercise in identification of skeletal remains for yourself.
Sex : Straightforward in intact bodies except in transvestites, adrenogenital syndrome and hermaphrodites. In mutilated/dismembered or charred bodies the internal sex organs, especially the uterus, cervix and prostate are resilient.
SEX DETERMINATION FROM SKELETON
Based on appearance of pelvis, skull, sternum, long bones. Pelvis is the most important bone for sex determination. Subjective and objective differences are seen between male and female pelves.
Subjective sex differences in the pelvis
MALE FEMALE
Pelvis as a whole Thick, heavy, markedly
muscular
Smoother, lifgter, more
spacious
Brim Heart shaped Circular or elliptical
Body of pubis Triangular shape Quadrangular
Sub pubic arch Inverted V shaped Inverted U shaped
Greater sciatic notch Deep and narrow Broad and shallow
Sacro iliac joint Large Small
Sacrum Long and narrow Short and wide
Objective sex determination from pelvis is based on anatomical pelvic measurements.
SEX DETERMINATION FROM SKULL
Supra orbital ridges
Mastoid process
Palate
Orbit
Mandible
Inexperienced persons can correctly sex over 90% of caucasian skeletons but only 83% of skeletons of Americaegros.
RACE DETERMINATION FROM BONES
The skull is the only reliable bone. It is not possible to narrow down the identification to racial stock:
• Caucasian (all whites)
• Negro (all blacks – African, American Negroes and West Indians)
• Mongoloid (Chinese, Japanese, American Indians)
Thus skulls of British, Germans, French or Swedes cannot be distinguished from one another.
Similarly Japanese skulls are similar to Chinese skulls.
Mongoloid race has characteristically “shovel-shaped” concave upper incisor teeth.
Cheekbones (Zygomatic arches): determine facial width. More prominent in Mongoloids. Width between eyes greater in mongoloids. Nasal openings: Wider and flatter in Negroids. Narrow in Caucasians.
Femur: Tends to be straighter in Negroids.
DETERMINATION OF STATURE FROM BONES
Long bone length (femur, tibia, humerus) is proportional to height. Tables are used. Fairly reliable up to the age of epiphyseal fusion. There are sex, race, nutrition and personal variations to consider.
AGE DETERMINATION FROM SKELETON
Sex has to be taken into account as bone development and epiphyseal fusion is different between the sexes.
Epiphyseal fusion. The pattern of fusion of bone ends (epiphysis) to bone shaft (metaphysis) in each bone indicates age. Charts & tables are used. Cranial suture fusion is less reliable. Pubic symphysis changes slightly with age. Arthritic changes, osteophytes and osteoporosis give further clues.
Ossification centres. Useful only in foetuses and babies. May be determined radiologically or by cutting into ossification centres. May be confirmed histologically. Most important centre in medico-legal work is the distal centre of the femur. This is present at birth and indicates a full term baby.
THE DATING OF HUMAN SKELETAL REMAINS
Are they ancient or modern bones? (i.e. greater or less than 50 years). Rate of skeletonisation is highly variable. In the tropics a body can be reduced to a skeleton in 3 weeks. Remarkable preservation of body is seen in acidic peaty soil (e.g. “Pete Bogg” from
Naked eye appearance is unreliable:
Tags of soft tissue, periosteum, ligaments etc, indicate less than 5 years old.
Soapy texture of surface indicates age less than a few decades.
Light, crumbling bones are likely to be a century or more old.
Laboratory tests –
1. Immunological reaction between bone extract and anti human serum ceases within
months of death.
2. If blood pigments are present bones are usually less than 10 years old.
3. Up to 20 amino acids may be identified in bones less than a century old.
4. Fluorescence of freshly sawn bone surface under UV light diminishes after 100 years.
5. New bones contain 4.0 – 4.5 gms% nitrogen; 2.5 gms% indicates approximately 350
years.
7. Radioactive carbon dating indicates which century. Individualising skeletal features Bone disease (Paget’s disease, tumours) Previous injury to bone (fracture callus, prosthesis, metallic fragments). Comparison of trabecular pattern of bone. Pattern of skull’s frontal air sinuses. Outline is unique and comparisons with antemortem X-rays are useful. Facial reconstruction Skull can be scanned into a computer and “fleshed” by computer reconstruction to give likely facial appearance in life. Unfortunately eye colour, hair colour and lips are independent of bony structure.
Examination and Documentation
of the Crime Scene
by George Schiro
Forensic Scientist
Louisiana State Police Crime Laboratory
Examination of the Crime Scene
Before the investigators begin examining the scene of the crime, they should gather as much information as possible about the scene. Once again, a slow and methodical approach is recommended. Information is gathered to prevent destruction of valuable and/or fragile evidence such as shoeprints, trace evidence, etc. Once all of the information is gathered, a mental plan is formulated as to how the crime scene will be analyzed. Copious notes and relevant times should be kept on every aspect of the crime scene investigation. The examination of the scene will usually begin with a walk through of the area along the “trail” of the crime. The trail is that area which all apparent actions associated with the crime took place. The trail is usually marked by the presence of physical evidence. This may include the point of entry, the location of the crime, areas where a suspect may have cleaned up, and the point of exit. In some cases, a walk through may become secondary if potential evidence is in danger of being destroyed. In that case, this evidence should be preserved, or documented and collected as quickly as possible.
The purpose of the walk through is to note the location of potential evidence and to mentally outline how the scene will be examined. The walk through begins as close to the point of entry as possible. The first place the investigators should examine is the ground on which they are about to tread. If any evidence is observed, then a marker should be placed at the location as a warning to others not to step on the item of interest.
A good technique to use indoors on hard floors is the oblique lighting technique (also known as side lighting). A good flashlight with a strong concentrated beam is the only tool needed. The room should be darkened as much as possible. If a light switch which a suspect may have touched needs to be turned off, then make sure the switch has been dusted for fingerprints first. Do not close any blinds or shades until after all general photographs have been taken. In the side lighting technique, a flashlight is held about one inch from the floor. The beam is then angled so that it just sweeps over the floor surface and is almost parallel to the surface. The light is then fanned back and forth. Any evidence, such as trace evidence and shoeprints, will show up dramatically. Under normal lighting conditions, this evidence may be barely visible or completely invisible.
As the walk through progresses, the investigators should make sure their hands are occupied by either carrying notebooks, flashlights, pens, etc. or by keeping them in their pockets. This is to prevent depositing of unwanted fingerprints at the scene. As a final note on the walk through, the investigators should examine whatever is over their heads (ceiling, tree branches, etc.). These areas may yield such valuable evidence as blood spatters and bullet holes. Once the walk through is completed, the scene should be documented with videotape, photographs, and/or sketches.
Documenting the Crime Scene
Videotaping the Crime Scene
If available, a video camera is the first step to documenting a crime scene. Videotape can provide a perspective on the crime scene layout which cannot be as easily perceived in photographs and sketches. It is a more natural viewing medium to which people can readily relate, especially in demonstrating the structure of the crime scene and how the evidence relates to the crime. The video camera should have a fully charged battery as well as date and time videotape display functions. A title generator and “shake free” operations are also nice options. If a title generator is not available, then about 15 seconds at the beginning of the tape should be left blank. This will allow the addition of a title card with any pertinent information to the beginning of the crime scene tape. The condition of the scene should remain unaltered with the exception of markers placed by the investigators and any lights turned on during the walk through. These alterations can be noted on the audio portion of the tape. Before taping, the camera range should be cleared of all personnel. Any people in the area should be forewarned that taping is about to commence and they should remain silent for the duration of the tape. This prevents recording any potentially embarrassing statements.
Once the video camera begins recording, it should not be stopped until the taping is complete. The key to good videotaping is slow camera movement. A person caever move too slowly when videotaping, yet it is all too easy to move the camera fast without realizing it. This is why videotaping is not ideal for viewing detail. People have a tendency to pan past objects in a manner that does not allow the camera to properly capture the object. This is why slow panning of an area is necessary and it should be panned twice in order to prevent unnecessary rewinding of the tape when viewing.
The taping should begin with a general overview of the scene and surrounding area. The taping should continue throughout the crime scene using wide angle, close up, and even macro (extreme close up) shots to demonstrate the layout of the evidence and its relevance to the crime scene. If videotaping in a residence, the camera can show how the pertinent rooms are laid out in relation to each other and how they can be accessed. This is sometimes lost in photographs and sketches. After the taping is complete, it is wise to leave about 15 seconds of blank tape to prevent the crime scene tape from running into anything else previously recorded on the tape. The tape should then be transferred to a high quality master tape. The recording tabs should be removed from the master tape after transferring the crime scene tape and the master should be stored in a safe place. This is to prevent accidental erasure of the crime scene tape. Copies can then be made from the master tape.
Still Photography
Whether a video camera is available or not, it is absolutely essential that still photographs be taken to document the crime scene. If a video camera is available, then photographs will be the second step in recording the crime scene. If video is not available, then still photography will be the first step. Photographs can demonstrate the same type of things that the videotape does, but photographs from the crime scene can also be used in direct comparison situations. For example, actual size photographs (also known as one-to-one photos) can be used to compare fingerprint and shoeprints photographed at the crime scene to known fingerprints or shoes from a suspect. This is the advantage of photographs over videotape.
Almost any type of camera with interchangeable lenses and a format of 35mm or larger will do in crime scene photography. The lenses should include a 28mm wide angle lens, a normal 55mm lens, and a lens with macro capabilities (1:4 or better). The flash unit used with the camera should be one that is not fixed to the camera. It should be able to function at various angles and distances from the camera. This is to allow lighting of certain aeras to provide maximum contrast, place the flash in hard to reach areas, and reduce flash wash out which can render the item photographed invisible. Print and/or slide color film (25-400 ISO) should be used. A tripod, a level, and a small ruler should also be available for one-to-one photography. It may be of help to the investigation to have a Polaroid camera handy for instant photographs. For example, an instant photograph of a shoeprint found at a crime scene can be provided to investigators who are running a search warrant on a suspect’s residence. The photo will tell them the type of shoe for which they are searching.
The photography of the crime scene should begin with wide angle photos of the crime scene and surrounding areas. When shooting the general overall scene, the photos should show the layout of the crime scene and the overall spatial relationships of the various pieces of evidence to each other. A good technique to use indoors is to shoot from all four corners of a room to show its overall arrangement. The next set of photos should be medium range to show the relationships of individual pieces of evidence to other pieces of evidence or structures in the crime scene. Finally, close up photos should be taken of key pieces of evidence. A ruler should be photographed with items where relative size is important or on items which need to have one-to-one comparison photographs. The object should first be photographed as is, then photographed with the ruler. It is important that when doing one-to-one photography that the ruler is on the same plane as the object being photographed and the film plane is parallel to the ruler. This is why a level and a tripod are necessary. Notes should also be taken as to what the investigator is photographing or wishes to demonstrate in each photograph. This is to prevent the investigator from getting the picture back at a later date and trying to figure out what he or she was trying to accomplish with the photo. The same areas should be photographed in the same sequence as mentioned above in the paragraphs on videotaping.
Crime Scene Sketching
The final phase in documenting the scene is making a crime scene sketch. The drawback of photographs is that they are two-dimensional representations of three-dimensional objects. As a result, most photographs can distort the spatial relationships of the photographed objects causing items to appear closer together or farther apart than they actually are. If spatial relationships of the evidence are important or if something needs to have proportional measurements included in it for calculations (such as bullet trajectory angles, accident reconstructions, etc.) then a sketch must be made of the crime scene.
A sketch is usually made of the scene as if one is looking straight down (overhead sketch) or straight ahead (elevation sketch) at a crime scene. A rough sketch at the scene is usually made first on graph paper in pencil with so many squares representing so many square feet or inches. Directionality of the overhead view is determined by using a compass. Using a tape measure or other measuring devices, measurements are taken at crime scene of the distances between objects and/or structures at the crime scene. These measurements are proportionally reduced on the rough sketch and the objects are drawn in. Two measurements taken at right angles to each other or from two reference points will usually suffice in placing the objects where they belong in a sketch. Double measurements should also be taken to make sure they are correct. This is especially true where calculations will later be used. A final sketch can be made later using inks, paper, and ruler, or a computer. The original rough sketch should be retained and preserved in case it is needed at a later date. Once the scene has been thoroughly documented then the evidence collection can commence.
Collection and Preservation
of Evidence
by George Schiro
Forensic Scientist
Louisiana State Police Crime Laboratory
Once the crime scene has been thoroughly documented and the locations of the evidence noted, then the collection process can begin. The collection process will usually start with the collection of the most fragile or most easily lost evidence. Special consideration can also be given to any evidence or objects which need to be moved. Collection can then continue along the crime scene trail or in some other logical manner. Photographs should also continue to be taken if the investigator is revealing layers of evidence which were not previously documented because they were hidden from sight.
Most items of evidence will be collected in paper containers such as packets, envelopes, and bags. Liquid items can be transported ion-breakable, leakproof containers. Arson evidence is usually collected in air-tight, clean metal cans. Only large quantities of dry powder should be collected and stored in plastic bags. Moist or wet evidence (blood, plants, etc.) from a crime scene can be collected in plastic containers at the scene and transported back to an evidence receiving area if the storage time in plastic is two hours or less and this is done to prevent contamination of other evidence. Once in a secure location, wet evidence, whether packaged in plastic or paper, must be removed and allowed to completely air dry. That evidence can then be repackaged in a new, dry paper container. UNDER NO CIRCUMSTANCES SHOULD EVIDENCE CONTAINING MOISTURE BE PACKAGED IN PLASTIC OR PAPER CONTAINERS FOR MORE THAN TWO HOURS. Moisture allows the growth of microorganisms which can destroy or alter evidence.
Any items which may cross contaminate each other must be packaged separately. The containers should be closed and secured to prevent the mixture of evidence during transportation. Each container should have: the collecting person’s initials; the date and time it was collected; a complete description of the evidence and where it was found; and the investigating agency’s name and their file number.
Each type of evidence has a specific value in an investigation. The value of evidence should be kept in mind by the investigator when doing a crime scene investigation. For example, when investigating a crime he or she should spend more time on collecting good fingerprints than trying to find fibers left by a suspect’s clothing. The reason is that fingerprints can positively identify a person as having been at the scene of a crime, whereas fibers could have come from anyone wearing clothes made out of the same material. Of course if obvious or numerous fibers are found at the point of entry, on a victim’s body, etc., then they should be collected in case no fingerprints of value are found. It is also wise to collect more evidence at a crime scene thaot to collect enough evidence. An investigator usually only has one shot at a crime scene, so the most should be made of it.
The following is a breakdown of the types of evidence encountered and how the evidence should be handled:
Fingerprints
Fingerprints (also includes palm prints and bare footprints) are the best evidence to place an individual at the scene of a crime. Collecting fingerprints at a crime scene requires very few materials, making it ideal from a cost standpoint. All non-movable items at a crime scene should be processed at the scene using gray powder, black powder, or black magnetic powder. Polaroid 665 black and white film loaded in a Polaroid CU-5 camera with detachable flash should be used to make one-to-one photographs of prints which do not readily lift. All small transportable items should be packaged in paper bags or envelopes and sent to the crime lab for processing. Because of the “package it up and send it to the lab” mentality, some investigators skim over collecting prints at a crime scene. Collecting prints at the crime scene should be every investigator’s top priority. Fingerprints from the suspect as well as elimination fingerprints from the victim will also be needed for comparison (the same holds true for palm and bare footprints).
Bite Marks
Bite marks are found many times in sexual assaults and can be matched back to the individual who did the biting. They should be photographed using an ABFO No. 2 Scale with normal lighting conditions, side lighting, UV light, and alternate light sources. Color slide and print film as well as black and white film should be used. The more photographs under a variety of conditions, the better. Older bitemarks which are no longer visible on the skin may sometimes be visualized and photographed using UV light and alternate light sources. If the bitemark has left an impression then maybe a cast can be made of it. Casts and photographs of the suspect’s teeth and maybe the victim’s teeth will be needed for comparison. For more information consult a forensic odontologist.
Broken Fingernails
Much like a bullet that has individualizing striations on it, natural fingernails have individualizing striations on them. A broken fingernail found at a crime scene can be matched to the individual it came from many months after the crime has been committed. Broken fingernails should be placed in a paper packet which is then placed in a paper envelope. It can then be transported to the crime lab for analysis. Known samples from the suspect and maybe from the victim will be needed for comparison.
Questioned Documents
Handwriting samples can also be matched back to the individual that produced them. Known exemplars of the suspected person’s handwriting must be submitted for comparison to the unknown samples. Questioned documents can also be processed for fingerprints. All items should be collected in paper containers. For more information consult a questioned documents examiner.
Blood and Body Fluids
If using the RFLP method of DNA analysis, then blood and seminal fluid can be matched back to an individual with a high degree of probability. Currently, if using the PCR method of DNA analysis or conventional serological techniques then blood and some body fluids can be said to come from a certain population group to which the individual belongs. As PCR technology advances, these population groups will become smaller, eventually giving it the same discriminating power as RFLP analysis has today. Dried blood and body fluid stains should be collected in the following manner: If the stained object can be transported back to the crime lab, then package it in a paper bag or envelope and send it to the lab; if the object cannot be transported, then either use fingerprint tape and lift it like a fingerprint and place the tape on a lift back; scrape the stain into a paper packet and package it in a paper envelope; or absorb the stain onto 1/2″ long threads moistened with distilled water. The threads must be air dried before permanently packaging. For transportation purposes and to prevent cross contamination, the threads may be placed into a plastic container for no more than two hours. Once in a secure location, the threads must be removed from the plastic and allowed to air dry. They may then be repackaged into a paper packet and placed in a paper envelope. Wet blood and body fluid stains should be collected in the following manner: all items should be packaged separately to prevent cross contamination, if the item can be transported to the crime lab, then package it in a paper bag (or plastic bag if the transportation time is under two hours), bring it to a secure place and allow it to thoroughly air dry, then repackage it in a paper bag. If the item cannot be transported back to the lab, then absorb the stain onto a small (1″x1″) square of pre-cleaned 100% cotton sheeting. Package it in paper (or plastic if the transportation time is less than two hours), bring it to a secure place and allow it to thoroughly air dry; then repackage it in a paper envelope. UNDER NO CIRCUMSTANCES SHOULD WET OR MOIST ITEMS REMAIN IN PLASTIC OR PAPER CONTAINERS FOR MORE THAN TWO HOURS. Victim and suspect’s known whole blood samples will have to be collected in yellow, red, or purple top “Vacutainers.” Contact the lab to which the samples will be submitted for specific information.
Firearms and Toolmarks
Bullets and casings found at the crime scene can be positively matched back to a gun in the possession of a suspect. Bullets and casings can also be examined at the crime lab and sometimes tell an investigator what make and model of weapons may have expended the casing or bullet. A bullet found at the crime scene can sometimes be matched back to the same lot of ammunition found in a suspect’s possession. Toolmarks can be positively matched to a tool in the suspect’s possession. Firearm safety is a must at any crime scene. If a firearm must be moved at a crime scene, never move it by placing a pencil in the barrel or inside the trigger guard. Not only is this unsafe, but it could damage potential evidence. The gun can be picked up by the textured surface on the grips without fear of placing unnecessary fingerprints on the weapon. Before picking up the gun, make sure that the gun barrel is not pointed at anyone. Keep notes on the condition of the weapon as found and stops taken to render it as safe as possible without damaging potential evidence. The firearm can then be processed for prints and finally rendered completely safe. FIREARMS MUST BE RENDERED SAFE BEFORE SUBMISSION TO THE CRIME LAB. The firearm should be packaged in an envelope or paper bag separately from the ammunition and/or magazine. The ammunition and/or magazine should be placed in a paper envelope or bag. It is important that the ammunition found in the gun be submitted to the crime lab. Any boxes of similar ammunition found in a suspect’s possession should also be placed in a paper container and sent to the crime lab. Casings and/or bullets found at the crime scene should be packaged separately and placed in paper envelopes or small cardboard pillboxes. If knives (or other sharp objects) are being submitted to the lab (for toolmarks, fingerprints, serology, etc.), then the blade and point should be wrapped in stiff unmovable cardboard and placed in a paper bag or envelope. The container should be labeled to warn that the contents are sharp and precautions should be taken. This is to prevent anyone from being injured.
Shoeprints and Tire Tracks
Shoeprints and tire tracks can be matched positively to a pair of shoes or to tires in a suspect’s possession. Shoeprints and tire tracks can sometimes tell investigators what type of shoes or tires to look for when searching a suspect’s residence or vehicles. Before any attempt is made at collecting shoeprints or tire tracks, one-to-one photographs should be made using a tripod, ruler, and level. The flash should be held at about 45 degree angles from the surface containing an impression. Casts can be made of impressions using dental stone. Once hardened, the cast can be packaged in paper and submitted to the lab. When photographing prints on hard flat surfaces the flash should be used as side lighting. Shoeprints on hard flat surfaces can also sometimes be lifted like a fingerprint. Dust prints on certain surfaces can be lifted with an electrostatic dustprint lifter.
Fracture Matches
Fracture matches can positively link broken pieces at the scene with pieces found in the possession of a suspect. For example, headlight fragments found at the scene of a hit and run could be positively matched to a broken headlight (just like putting together a jigsaw puzzle) on a suspect’s vehicle. Larger fragments should be placed in paper bags or envelopes. Smaller fragments should be placed in a paper packet and then placed in an envelope.
Hair
If a root sheath is attached, then DNA analysis using PCR technology can say that this hair came from a certain percentage of the population to which the suspect belongs. If there is no root sheath, then a microscopic analysis can say that the hair has the same characteristics as the suspect’s hair and is similar to his or her hair. At this point, no one can say that a hair came from a particular individual. Hair found at the scene should be placed in a paper packet and then placed in an envelope. If a microscopic examination is required, then 15-20 representative hairs from the suspect must be submitted to the lab for comparison. If DNA analysis if going to be used, then a whole blood sample from the suspect must be submitted to the lab in a “Vacutainer.” Contact a DNA lab for more information.
Fibers
Fibers can be said that they are the same type and color as those found in a suspect’s clothes, residence, vehicle, etc. Fibers should be collected in a paper packet and placed in an envelope. Representative fibers should be collected from a suspect and submitted to the lab for comparison.
Paint
Paint can be said that it is the same type and color as paint found in the possession of a suspect. Paint fragments should be collected in a paper packet and placed in an envelope. Representative paint chips or samples should be collected from the suspect and submitted to the lab for comparison.
Glass
Glass can be said that it has the same characteristics as glass found in the possession of a suspect. Smaller glass fragments should be placed in a paper packet and then in an envelope. Larger pieces should be wrapped securely in paper or cardboard and then placed in a padded cardboard box to prevent further breakage. Representative samples from the suspect should be submitted to the lab for comparison.
Other Trace Evidence
Sometimes during the commission of a crime, there are other items which may be transferred to a perpetrator from the scene or from the perpetrator to the scene (sheetrock, safe insulation. etc.). The guidelines for collecting the evidence and obtaining known samples is about the same as for paint and fibers. For specific information, contact your crime lab.
Special Considerations for
Sexual Assualt Evidence
by George Schiro
Forensic Scientist
Louisiana State Police Crime Laboratory
When dealing with sexual assaults, the investigator usually has a living victim who can provide the investigator with information which will help in collecting and preserving the pertinent evidence. The investigator should glean as much information as possible, so he or she will know which evidence to collect. For example, if the victim tells the investigator (which in this case may be the examining physician) that no oral penetration occurred, then the investigator knows that no oral swabs will need to be taken. Any information should be passed on to the crime lab, so the forensic scientists will know how to process the evidence submitted. Evidence should never be submitted without communicating relevant information.
When dealing with sex crimes, the victim should be taken to the hospital immediately and the examination started as soon as possible. Photographs should be taken to document any injuries which the victim received. If necessary, oral, vaginal, and/or anal swabs should be taken from the victim and air dried for one hour in a moving air source as soon as possible. They should be collected as soon as possible because the body begins breaking down the various components in seminal fluid through drainage, enzyme activity, pH, etc. The swabs should be air dried under a fan for at least one hour. This can either be accomplished by the doctor at the hospital, or, upon collecting the kit from the doctor, the investigator should bring it immediately to a secure place and air dry it. The reason for this is that the moisture in the swabs allows microorganisms to grow which can destroy the evidentiary value of the swabs. Known saliva samples from the victim must also be air dried along with any other wet or moist samples (not including whole blood samples, vaginal washing or any other liquid samples collected).
Usually, the best sample of seminal fluid comes from the swabs, as long as they are preserved properly. The next best place is usually the victim’s panties because the seminal fluid will drain into the panties (if the assault was vaginal or anal iature). The stain will sometimes be better preserved because the seminal fluid tends to dry faster in the panties. If the panties have wet stains, then they should be air dried as soon as possible before packaging. Clothes can be a good source of seminal fluid if the assailant ejaculated on the victim’s clothes. The clothes can also be a source for the suspect’s blood, hairs, fibers, or other evidence transferred to the victim from the suspect. Clothing should be air dried before permanent packaging and each article of clothing should be packaged separately.
Bed sheets, comforters, spreads, etc. can also be a source of evidence from the suspect. The value of this type of evidence should be carefully considered by the investigator before collecting it. If the bed is a “high traffic” area, meaning that numerous people have had access to the bed and the bed sheets haven’t been cleaned in a long time, then it won’t have as much evidentiary value as a bed where only one person had access to it and the sheets have been cleaned recently. The investigator should use the side lighting technique to look for any loose trace evidence on the sheets which may be lost during handling and packaging. This evidence should be placed in a paper packet and then placed in an envelope. If the sheets have wet stains and these can be attributed to the rape, then the investigator should circle these stains and inform the crime lab that those are the relevant stains to be examined. The investigator should note that he or she circled the stains and as always, air dry the evidence before permanently packaging it. The investigator should neatly fold the sheets inward to prevent the loss of any other loose evidence. The sheets can then be packaged separately in paper bags, air dried if necessary, and submitted to the crime lab.
If a suspect is established in a rape case, then reference samples should be collected from the suspect for comparison. These samples should include: a whole blood sample in a red, yellow, or purple top “Vacutainer”; a saliva sample (air dried); 15-20 pulled head hairs; and 15-20 pulled pubic hairs. If the suspect is captured within 24 hours and it can be established which clothes and/or shoes he wore during the attack, then the items should be packaged separately and submitted to the crime lab. Sometimes trace evidence from the victim such as hairs, fibers, blood, etc. can be found on the suspect’s clothing.
Searching and Examining
a Major Case Crime Scene
By H.W. “Rus” Ruslander, S.C.S.A.
Palm Beach Co. S.O., West Palm Beach, Fla.
I. The Initial Death Scene Examination
The crime scene examination and subsequent search should be done in a careful and methodical manner. After talking to the officer(s) who were the first ones on the scene and learning from them of any changes that might have been made to the scene since their arrival, such as turning lights on or off or opening doors or windows, start the examination by working your way into the body using great care to avoid disturbing or destroying any evidence as you do. Carefully observe the floor or ground surrounding the body. Look for items of evidence or of evidential value such as stains, marks, etc. Remember to look up too, every crime scene is 3 dimensional. Another technique to you assist in locating evidence is to shine a flashlight on the ground at an oblique angle. Yes, even in the daytime. Look at the items as they are located. Pay close attention to everything as you approach the body at this time, do not dismiss anything until its evidentuary value can be determined. Are there any footprints or drag marks? Is there anything on the floor or ground that may be stepped on or destroyed?
Only one investigator at a time should approach the body! Determine what, if anything, has been moved or altered by the suspect(s) or anyone else prior to your arrival. Has the body been moved? If so, by whom and for what reason?
Never move or alter the positioning of the body! Make close visual examinations of the body and the area immediately around it. Look between the arms and legs without moving them. Look at the arms, hands and fingers. Are there defense wounds? Is there anything under the nails that you can see at this time? If you can, try to determine the cause of death and the instrument or method used. Take careful notes of the external appearance of the body and the clothing or lack of clothing. Look at or for lividity, decomposition, direction of blood flow patterns, remember the law of gravity. Is the blood flow consistant with it? Make detailed notes.
Describe the clothing, and especially the condition of the clothing. Do folds or rolls indicate the body had been dragged? If so, in what direction? Note those folds and rolls, diagram them then photograph them. They could assist you in determining the method of transportation or placement of the body at the location where it was found. There could be trace evidence in the folds and rolls too.
Describe the location and appearance of wounds, bruises, etc. Make careful and detailed observations. Describe not only what you see, but also what you do not see! Forget about what you think you see! If something is missing, note it. For example, if you observe an area on the wrist that is not tanned by the sun, note it. DO NOT state that a wristwatch is missing. What if the victim had an I.D. bracelet or sweatband on instead? Never ASSUME! Examine the scene for the presence and absense of blood. If any is located, note the amount, size and shape of the drops and degree of coagulation or separation of it. Photograph it using a scale and always taking the pictures from a 90 degree angle.
At this time, you should be making a sketch of the scene. It can be a rough, freehand sketch drawn on a blank piece of paper or in your notebook. You should include in the sketch things like the location of all doors, windows, furniture, the victim and anything else you feel it is necessary to document. A sketch should be made in all murder cases and any other case involving a death where there is any question of cause or at the discretion of the investigator. Measurements can then be made of the location to show the size of the area drawn, the width and height of doors, windows, tables, the bed or any other items needed. This will also geographically locate the victims body and items of evidence within the scene. If the investigator is reasonably sure this is not a natural death and he/she is going to proceed with the investigation as if it is a murder, then at a later date, a detailed formal diagram should be drawn using drafting tools, a scale and a uniform format. Photos of the scene can give a distorted view of the relationship of the body to other fixed objects due to camera angle, size of lense, lighting, etc. To accurately depict the scene it is possible to use photos in conjunction with the finished diagram. Something to keep in mind about the sketch is this, you should have enough information in it so you could give it to another investigator and that person would be able to complete a finished diagram without the need to revisit the scene.
II. Photographs
The investigator should have the photographer, if one is available, or, if not that lucky, then the investigator himself should ensure that;
Overall photos of the scene are taken to show the approach to the area, street signs, street light locations in relation to the actual scene, street addresses and identifying objects at the scene. Pictures should also be taken of every room in the house, even if their relationship to the crime scene is not readily apparent.
Photograph the scene in a clockwise pattern before altering the body’s position or any other evidence within the scene. Photograph the scene from at least 2 opposite corners, but from all four corners is even better. This way, nothing is missed or hidden from view by intervening objects.
Photograph the body and the immediate vicinity around the body. If you have a camera boom, take pictures from ceiling height down of the victim and any other evidence. This perspective often shows things missed when viewed from ground or eye level.
Keep a photo log.
Another idea to keep in mind when photographing the exterior of an indoor scene or an exterior scene is to take photos of the spectators who are standing around watching the activities. Many times the perpetrator will return to observe the actions of the police or fire personnel. This seems to be especially true in arson cases. Additionally, photos may help identify reluctant witnesses who can be identified and interviewed at a later time.
Once the photos are taken, the investigator should now make a detailed examination of the victim. Are the eyes and/or mouth open or closed, what is the color of skin, of the nails and hands or lips. The presence or absence of blood, saliva, vomit, lung purge, their direction and flow. The best idea is to begin at the head and work down to the feet. Look for cuts, bruises, stab wounds or bullet holes. Document maggot activity if present. When the body is moved, check the underside of the body for wounds and underneath the body for items of an evidentiary value. Record the temperature of the body, the surface it is laying on, and the interface area between the two. Obtain the ambient temperature. If a maggot mass is present, take the temperature of the mass.
Do not attempt to learn the victims identity by going through the pockets of the victims clothing. If his/her identity cannot be established by other means at the scene, the investigator can obtain this information when it is made available at the Medical Examiners office later. Identification photos and finger and palm prints should be taken at the Medical Examiners office too. In some jurisdictions these things can be done at the scene. If the Medical Examiner is comfortable with the competency of the crime scene investigators or if their forensic investigators are present to observe and document the actions of the crime scene investigators, some Medical Examiners will not have a problem with these things being done at the scene.
III. Notifying the Medical Examiner
The crime scene investigator, the detective or the supervisor on the scene should notify the medical examiner of the type of death case they are investigating. Since the determination of cause and manner of death often depends on the evidence recovered at the scene, the Medical Examiner may elect to respond to the scene personally or send one of his forensic investigators in his place.
The agency’s relationship with the Medical Examiners office is crucial to the successful investigation of any case. A relationship of trust and honesty is essential. Since any investigation requires a team effort, steps must be taken to ensure that a harmonious atmosphere is in place and remains that way.
There are certaiotifications that must be made during the preliminary investigation. The Medical Examiners Office should be notified and apprised of the situation as soon as possible after a murder has been discovered. They should also be notified if there is any unattended or suspicious death being investigated. If any change in status in the case occurs, they should be made aware of it. Florida law charges the Medical Examiner with determining the cause and manner of death in any case that he deems necessary, including but not limited to murder, unattended death cases, suicides and cases involving communicable diseases or public health hazards. The prompt notification will also result in the timely arrival of trained professionals who can assist the investigator in the determination of an approximate time of death.
IV. Continuing the Search
Search the immediate area around the body (divide the room into a grid and work outward from the body). Have another investigator retrace your steps and recheck the grids for any missed evidence. REMEMBER, all scenes are three dimensional, never forget too look up too! Do not touch areas or articles which have the possibility of being processed for latent fingerprints.
Expand the search to the remainder of the building or scene. Personal notepads, diaries, phone books and answering machines or the tapes in them are good sources of information. Check the caller I.D. unit. Missing personal belongings or items that have been moved or removed may provide valuable information.
The scope or intensity of the search of the scene depends on the particular situation and the conditions present. It would be difficult to proceed with a detailed examination of a scene without adequate lighting. To do so would probably result in the overlooking of evidence or the destruction of trace or latent evidence. It is impossible to describe all the possibilities which could occur in an improper search of a scene. In the end, it depends on the training, experience and judgement of the investigator and upon the same factors relating to those he/she calls on to assist. One final note, be cognizant of someones expectation of privacy or legal standing. If that possibility exists, a search warrant or written consent to search must be obtained.
V. Fingerprint Evidence
Latent prints are left by the contact of the palmar surfaces of the hands and/or bare feet of a person are probably the most valuable piece of evidence at any crime scene. The term “latent” means hidden, not visible. However, for the purpose of this instruction, a latent print is considered as one which is obtained in conjunction with an investigation involving a possible identification. There are three main types of prints which may be obtained in an investigation, they are; 1) visible or patent prints, 2) molded or plastic prints and 3) latent prints.
Visible or Patent Prints are those prints which have been made by transferring a foreign substance, such as ink, blood, grease or dust from the crests of the papillary ridges to the surface of the object touched. The most common type is the dust print. When a finger comes in contact with a thin layer of dust, some of the dust sticks to the friction ridges. When the finger subsequently comes in contact with or against a clean surface, a fingerprint results or, when the finger is removed from the surface, the ridges pull away the dust, leaving the fingerprint. This print in some cases may be so clear that it can be successfully searched in a single fingerprint file.
An excellent print may also be left when the finger is contaminated by other substances such as ink, soot, flour, paint, facial oils, etc. Fingerprints in blood are not uncommon in murder investigations, but can be indistinct and less reliable for identification. They could require chemical enhancement to make them identifiable.
Molded or Plastic Prints are those prints that occur when the finger touches or presses against a soft pliable surface such as putty, wax, an adhesive, grease, drying paint, blood or soap. Impressions in the skin of a deceased victim have also been observed. A negative or reversed impression of the friction ridge pattern is thereby produced as a molded or plastic print. Such a print may also be found in paint or recently painted objects or surfaces.
Latent Prints are those prints made by natural skin secretions such as perspiration, sebaceous oils and dirt being deposited on an object touched from the details in the friction ridge patterns. Latent prints are usually found on objects with smooth, polished surfaces or on paper. Under favorable conditions, however, they may also appear on rougher surfaces like tightly woven materials, starched fabrics, vegetation, wood or even human skin.
Photographing Prints found at the scene should always be photographed prior to attempting to lift them. This is recommended since it is much easier to introduce print evidence into court if it has been recorded. Especially since parts of the object on which the print was located will also be visible in the photograph. If a good lift is obtained during the investigation and it is identified as being that of the suspect, it may be necessary to have the photograph enlarged. Copies of the photos can also be made available for the attorneys and jurors. When taking the photos of the prints, always use a scale or other measuring devise and take the photo at a 90 degree angle to the surface to prevent any distortion to the print when it is being photographed. Make sure the scale is visible in the picture and that the inches or metric notation is visible. It is also a good habit to indicate where up is in the picture since the orientation of the print can be useful information.
Prints from sources other than fingers are also obtained at crime scenes. While it is usually true that more fingerprints are obtained in investigations than prints from any other papillary skin surface, it should be mentioned that any palmar (palm, wrist) or plantar (foot, toe) skin designs can also serve to positively identify the suspect. In some cases, lip and ear prints have also been recovered.
VI. Expanding the Search
Once the investigators have completed their examination and the body has been removed, the investigators should take time to systematically check the remainder of the house, business, vehicle or location and carefully note items of evidence or conditions which may shed any additional light on the investigation. These can include;
Doors, are they locked or bolted (from the inside or outside), are there marks of forced entry, does the doorbell work, is there a doorknocker, are there scratches around the keyhole, etc.
Windows, what type, are they locked or unlocked, open or broken, note the type and position of curtains, drapes or blinds.
Newspapers and mail, is the mail unopened or read or not, check the postmarks on envelopes and the dates of newspapers.
Lights, which ones were on when the crime was discovered, how are they controlled, by timers, motion sensors or switches. Can they be seen from the outside. Are the bulbs broken or unscrewed?
Smells, do you or did the first responding officer notice the smell of gas, tobacco, alcohol, perfume, gun powder or anything else unusual.
Kitchens, was food being prepared, if so, what kind (it may or may not correspond with the victims stomach contents). Is there food that was partially eaten, utensils, glasses or plates. Is the stove warm or still on, Are there signs of attempts to burn or wash away evidence. Are there signs of clean up attempts.
Heating/Air Conditioners, what type is it, is it vented or unvented (carbon monoxide can kill). What is the thermostat setting.
Are there signs of a party, such as empty bottles (note the labels, brands, types of liquor, etc.) are there cups, glasses and what is their contents, how many are there, is lipstick on any of them, how many places are set at the table.
Note contents of ashtrays, cigarette packs and butts, brands, the way in which the cigarettes were extinguished, is there tooth marks or lipstick on them. Remember, DNA is easily obtained from the butts, preserve them properly.
Contents of waste baskets and trash cans, has anyone been going through them looking for anything, is the trash in proper order (dates oewspapers, letters, etc.).
Clocks and watches, are they wind-up or electric. Are they running, do they show the right time, what time are alarm clocks set for. Check timers on VCR’s, microwave ovens, etc.
Bathrooms and vanities, are towels, rags etc. damp to touch or dry. Are they bloodstained. Check for signs that the suspect cleaned up afterwards or was injured and bled at the scene. Is the toilet seat and lid left up? In a womans house, this could be a piece of important information. Check medicine cabinets for drugs, check the tanks of toilets, that is a great place to hide things.
General disorder, is there evidence of a struggle, is the place just dirty, etc.
Shootings, how many bullets were fired, account for all of them if possible, find cartridge cases (number and location found) if there are any bullet holes (number and location), was the weapon left at the scene. There may be expended cartridge casings found laying on the floor, rug or on furniture. It is recommended to mark these items, after photographing them first, with numbered markers to prevent their being moved, altered or damaged. If necessary, they may be protected by placing water glasses over them.
Stabbing and beatings, was the instrument left at the scene, could it have come from that location or was it brought to the scene by the suspect.
Blood, document the location, degree of coagulation, type (spots, stains, spatters, pooling, etc.). Sketch and photograph the bloodstains. Remember, when a body fluid begins to decompose, it will discharge a reddish brown fluid which resembles blood, when describing this, be objective, call it what it is, a reddish brown fluid. Bloodspatter analysis may be used to reconstruct violent crimes. Carefully photograph all blood patterns using scales. DO NOT cover up patterns with the scales if possible. Remember, always look up, cast-off spatter will probably be on the ceiling.
Hangings and strangulation, what instrument or means was used, was it obtained in the house or brought to the scene, are there any portions remaining. If a suspected auto-erotic death, look for signs of prior activities such as rope marks on door frames or rafters. Be prepared for scene re-arranging by ashamed family members. Remember, do not cut the victim down if he/she is obviously dead until all aspects of the investigation have been covered. Never cut through the knot and always use a piece of string tied to each end of the cut to re-connect the circle.
Look at stairs, hallways, entries and exits to the scene, check for footprints, debris, discarded items and fingerprints. Attempt to determine the route used to enter and exit the scene by the suspect and avoid contaminating it.
Presence of items that do not belong there, many suspects, in the heat of the moment, will leave items of great evidential value, don’t overlook this possibility.
Is there signs of ransacking, to what degree, if any, has the scene been ransacked. Was anything taken (relatives and friends can assist in making this determination).
Look for hiding places for weapons which the suspect may have had to conceal quickly, check behind stoves, on top of tall furniture, behind books, among bedclothes, under the mattress, on the roof.
VII. Personal Information
Is the victim married or in a relationship? Determine as much about the state of the marriage or relationship as possible, for example, abuse, infidelity on either partners part, drug or alcohol abuse, monetary problems. Is there a suicide note, if so does it appear genuine or staged? Process for prints, get handwriting samples from the other occupants of the location. Has the victim threatened suicide recently, has he/she been despondent, what has happened recently to prompt or preclude such actions? Check the victims computer.
VIII. Curious Onlookers at the Scene
Many additional problems are caused by curious onlookers at the scene when a body is discovered. The major concern is, of course, to protect the scene from destruction or contamination by onlookers and curious police officers. The latter group usually presents the most problems. Police Officers are naturally curious and generally have to see things for themselves. Detailed follow-up investigations of many crimes have revealed that various items initially thought to be of great evidential value were actually left by curious police officers.
It will never be known how much valuable time has been wasted and how much evidence has been destroyed by the mere presence of policemen. Just standing around or leaning against a doorway may grind evidence into the ground or smear a good fingerprint. The investigator should explain these facts to the officers present and if the officers are not needed, request that they leave the scene. Most officers are cooperative and no difficulty should be encountered if the matter is presented properly. Occasionally, a problem presents itself when a high-ranking officer appears on the scene. If it becomes apparent that their presence could result in the destruction of evidence, their cooperation should be elicited in leaving the scene. The use of a log or name list of everyone entering the crime scene also helps discourage the curious. When good latent fingerprints are found, every person who has been present at the scene, including the victim, must be fingerprinted for identification and/or elimination purposes.
The police should use tact and courtesy when dealing with civilian witnesses and crowds. This approach serves several purposes. It will gain as much cooperation from people as possible under the circumstances and it may result in a witness, who is an onlooker, coming forward with valuable information. This is especially important in areas where past experiences indicates that the hostility of onlookers is easily aroused. In some situations, the mood of the crowd may become so ugly that the police are forced to leave the scene before they can complete their investigation.
Populated areas, usually consist of streets, sidewalks, communities, etc. and requires the presence of officers to protect the scene. If not, physical barriers such as crime scene tape, vehicles or sawhorses may be needed. In some cases, a detailed search of an entire area may be necessary. This can be done most effectively by cordoning off the area and dividing it into manageable sections to be searched individually. Remember, when setting the boundaries of the crime scene, make it cover as large an area as possible. It is much easier to shrink it down later that to try to expand it once the boundaries have been established. And a news cameraman is standing where you want to expant the scene to.
To avoid destroying evidence in areas of heavy weed or brush, a pathway may be marked off using string or flags and used as the sole entrance and exit to the scene until the search is finished. The pathway should be carefully examined first to ensure no evidence is lost.
Officers should never overlook the potential of any items found at or near the scene. Investigators should conduct a neighborhood canvass for witnesses.
In Rural Settings, many problems will present themselves that are found in urban settings. These are handled in the same manner as an urban investigation. However, there can be significant differences in a rural setting, these could include,
Accessibility or the lack of it. Are 4 wheel drive vehicles needed? Can it only be reached by boat or helicopter? Do you need to pack all your equipment in with you?
Length of time a body has been there prior to discovery. This will cause many changes to the scene such as decomposition, animal activity and weather related destruction of the evidence.
Use care not to disturb the ground that may have footprints or tire marks imbedded in it.
Employ aerial photography. It will provide information about routes or egress and exit to the area, traffic patterns and location of homes, etc. This is true in both rural and urban settings.
IX. Evidence
As a rule, in the absence of a crime scene investigator, the removal and submission of evidence should be restricted to the lead investigator or lead uniform officer. When evidence is discovered by persons other than the investigator, these items should be, if possible, pointed out to the investigator for his collection and removal to avoid a long list of witnesses or links in the ever growing chain of custody needed for court at a later date. Remember if the scene is being worked by a crime scene investigator, that is his/her scene. They are in command of the scene itself. All other law enforcement personnel present are there to assist that investigator.
There can be situations where the finder of the evidence should collect and log it rather than give it to the investigator. This will reduce the chain of custody but still requires the finder to advise the investigator of its discovery, location and identity. Any evidence so moved must be photographed first.
Evidence can be marked for proper identification. This can be nothing more than the recording of a serial number or the physical placement of your unique mark directly on the item. If marking items, make sure you do not cause the destruction of latent prints or other marks such as tool marks or ballistic identifiers. When submitting evidence;
Give a complete description of all evidence submitted including, date, time, location recovered and who recovered it.
Illustrate the chain of custody and indicate who will be needed to testify in court about that specific piece of evidence and why.
If a search warrant was obtained, include that information.
List the evidence recovered in a chronological order and include the exact location of recovery. This could include measurements.
X. Finally
The previously listed suggestions are provided as a basic guideline and are the opinion of the author. They are based on his experience, training and observations. They are not meant to be an exhaustive, complete list of actions to be taken at a crime scene. Each scene is unique. Each scene requires detailed and complete processing techniques. If you rely on the training you have received, the observation of others working their scenes and the lessons learned from working previous scenes of your own, you will continue to grow and evolve, providing your jurisdiction with the finest possible work product you are capable of producing.
