INJURIES nCAUSED BY SHARP OBJECTS.
FORENSIC nEXAMINATION nIN CASES OF nFIREARM INJURIES
INCISED WOUNDS
Syn: cuts, slashes From Lati n i ncidere– to cut into. Surgical term incision with nscalpel
Definition: Clean division of the full thickness nof skin (or other tissue) under the pressure of a sharp-edged instrument.
An incised wound is LONGER THAN IT IS DEEP ndue to swipe naction.
Instrument is sharp-edged, such as: knife (linear, clean), jagged metal n(irregular, jagged), broken glass
CHARACTERISTICS OF AN INCISION~
– clean cut, everted edges
– no tissue nbridges or abrasion of margins
– linear or nelliptical shape, often gapes
– often deeper at nstarting end
– jagged if ninflicted through loose, folded skin.
Chop wound is a variant of an incision. Has clean-cut edges but an abraded margin due to inversioand friction against the sides of the wide blade on insertion.
FORENSIC IMPORTANCE
Reflect sharp edge, not weapon type
No trace evidence
Profuse external haemorrhage nand air embolism
Danger to life depends on site and depth
Incised wounds may be Self-inflicted, assault or accident.
SELF INFLICTED
At sites of election (wrists, neck, cubital fossae, chest, abdomen, groin)
Suicidal cut Throat: tentative incisions (left side of neck if nright handed), one or more deep, sweeping cuts, down from the left, across the nmid-line, up towards the right ear. Sshallow deep centrally shallow. Cut slopes upwards and backwards. nIncision isusually through level of thyrohyoid ligament and may be down to spine! Repetitive nnicks at the base of the wound (sawing). Bleeding is venous, loss of nconsciousness is slow. Air embolism may occur.
OTHER SELF-INFLICTED INCISIONS
Fabricated nassault – superficial wounds to head, left arm, chest abdomen, thighs.
Parasuicidal mutilation – face, arms, trunk … low nself-esteem
ASSAULT INCISIONS
Compared to suicidal cuts, homicidal cuts:
– lack the unhurried election of site. May nbe aimed, but many miss.
– lie both higher and lower across neck
– no tentative ncuts, all are forceful and deepen rapidly
– no repetitioin same track
– slope backwards and downwards
– associated with ‘defence ninjuries’ to hands and arms
ACCIDENTAL INCISIONS
– random pattern
– usually single
– often deep and nforceful
PENETRATING WOUNDS
(Syn: Stab & nPuncture wounds) Puncture is “a small hole made with a sharp point” nDefinition: Penetrating injuries caused by separation of the skin and soft ntissues under the pressure of a sharp or blunt pointed instrument, the greatest ndimension being its depth.
ITS DEPTH EXCEEDS ITS LENGTH on the body nsurface.
Often appear trivial externally (short nincision or laceration) BUT often causes internal trauma and haemorrhage.
Caused by thrusting of (or falling onto) 3 ntypes of instrument
(1) Sharp and flat, e.g. knife STAB
(2) Sharp and thin, e.g. needle NEEDLE PUNCTURE
(3) Blunt, long and rigid, e.g. woodestake, spike, screwdriver, tooth PUNCTURE
WOUND
PENETRATING – passes into but not through norgan
PERFORATING OR TRANSFIXING – from Lati n p erforare, p er–t hrough & f orare– to bore passes through and through aorgan
STAB WOUNDS
Descriptors of penetrating wounds
a) Damage to clothing (slashes, stabs nthrough folds, blood flow & drip patterns, trace evidence)
b) Site in relation to anatomical nlandmarks, midline, heel.
c) Shape
d) Alignment (horizontal, vertical, noblique)
e) Size : length n& width with edges opposed
f) Direction :in n3 planes
g) Depth
h) Damage to tissues along track
i) Effects : nexternal & internal haemorrhage, pneumothorax, air embolism
Adequate description may provide vital ninformation about :
1) Type of weapon (c): usually a knife
2) Dimensions of the weapon (e)
3) Taper of blade (e)
4) Movement of knife in wound (c)
5) Direction of thrust (f)
6) Depth of thrust (g)
7) Amount of force used
8) Likely effect on victim (h, i)
WOUND LENGTH
A straight in and out stab wound is nslightly shorter than the width of the blade due to stretching of the skin over nthe point of the knife on insertion and elastic recoil on withdrawal. Wound nlength and width must be assessed with the edges taped together because the nwound is often shortened and widened into an ellipse by skin elasticity n(Langer’s lines of tension) and underlying muscle tone. Wound length < blade nwidth
(1) stretching of nskin over point on insertion and subsequent recoil on withdrawal.
(2) tapered blade nnot fully inserted
Wound length > blade width when blade ndoes not pass straight in and out – entry and withdrawal at angle.
“Rocking” nof knife on withdrawal. Cutting edge extends wound length The best indicator nof blade width nis nthe shortest (least rocking), deepest wound (weapon fully inserted)
SHAPE OF WOUND May indicate:
(1)Cross-sectional shape of knife blade e.g. – Double-edged blade –> Slit with ntwo sharp ends
N.B. single edged knife may give similar nwound due to clean splitting over blunt end
– Thin, single edge blade –> nTriangular slit, one sharp end
– Thick, single-edged blade –> Slit nwith one sharp and one ‘fishtail’ end due to stretching & laceration over nblunt edge
Stab wounds are typically elliptical with nclean cut edges and no bruising or abrasion of margins (incision)
(2) Direction of insertion overhang of upper edge, bevel of lower nedge N.B. The direction of the wound track through the tissues is assessed at npost mortem, with the body lying flat on its back. The position of the internal norgans is different in life, when standing, sitting and breathing.
(3) Movement of instrument on withdrawal
Small change in angle –> notch nTwisting –> crescentic wound
WOUND TRACK DEPTH
< length of ninstrument if not fully inserted
> length of ninstrument if fully inserted and body surface compressed e.g. abdomen, chest.
A small penknife can perforate heart or nabdominal aorta.
EFFECTS OF STABBING
Victim may not initially be aware of ninjury. There may be little or no external blood loss. Internal blood loss may nbe profuse and rapidly fatal or slow enough to allow time for medical ntreatment. Main effect is bleeding. The time taken to incapacitate the victim nand what actions are still possible is very difficult to estimate. A stab to nthe heart nmay nbleed profusely out into the confined space of the pericardium. If pericardial ndefect is small or does not communicate with the pleural cavity ncardiac tamponade may result (200-450ml). Left ventricular wound may partially reseal, resulting islow blood loss or spontaneous healing. Thin-walled right ventricle less nlikely. Great vessels do not re-seal. Rate of bleeding from stab wound to the lung depends on the size of vessels cut. Large npulmonary veins & arteries branch outwards from the hilum. nPeripheral stab bleeds less and may seal if lung collapses. Pneumothorax nmay itself be fatal. Cut through bronchus may bleed and obstruct airways.
Abdominal stab may penetrate major vessels, liver or nspleen with rapid haemorrhage into the abdominal ncavity. Stabbing to the head and face may allow penetration of bone in the regioof the eye, nose and temple where bone is relatively thin. Pulmonary air embolism originating in a partially severed jugular nvein may be rapidly fatal before much blood is lost. Severing na carotid artery or jugular vein results in rapid exanguination.
The surface of object, which colliding with body, operates ocloths, cutting, disconnecting or nslitting them, is called sharp, and suitable objects sharp. The damages, that are generated nfrom them, compose a damages group by sharp objects. Another nwords any object, which has nsharp edge or sharp end (or that and other together), is termed in forensic nmedicine as sharp.
Sharp we name such objects, which, operating on man body whether his nclothes by its edge whether end, cause damage with some properties. These properties depend on specific (group) npeculiarities of sharp objects.
The sharp objects are classified differently.
nCutting instruments
nStab instruments
nChopping instruments
By typical man body damages, that are ngenerated from action of sharp objects, present dependence on article nappearance and of mechanism of his naction on cloths contradistinguish cut, chopped, nsting-cut wounds. All of they ncharacterize by some signs, inherent nfor action of certain sharp objects. nThese wounds signs we name general. They enable to distinguish the wounds, entailed by sharp objects, from wounds, drifted by blunt objects whether shot from fire-arms. But for these signs it is impossible to define nappearance of sharp object.
Typical morphological appearances of wounds ncaused by sharp objects:
● nDefinite shape: fissure-like, nstar-like
● nThere margins are regular, without ntears, bruises and abrasions
● npointed ends, sometimes with slight ntears
● nabsence of connective-tissue nmembranes between the margins
Injuries caused by ncutting instruments
The Cutting objects are characterized by blade (ribbing, nin which borders, that intersect, converge under sharp corner, besides rib this is still sharpen) and also nlight weight (knife, razor, than, plait, npiece of glass, tin, sharp edge stone, bone piece and etc.).
Damages formation Mechanism by cutting objects ninclude pressing or impaired part of nbody and simultaneous object motion on his nsurface. If to take a sharp razor and few to press by her blade on skin in nperpendicular direction, then damage will not happen. nBut already small motion along lengthwise to landmark will bring on skin cut – nwill grow up sword-cut. So, in forming nmechanism of sword-cut major sense has a blade sliding attached to small pressure. At the same timed, by what pressure and by what nlonger blade extent, that most and more deep arise wounds.
We can diagnose action of ncutting objects for such specific (whether group) wounds signs:
● their nshape are C-like, S-like, Z-like
and attached to nsummary edges linear (in tie with what nhas only length), and their clear spaces in appearance of overturned triangle. nTypical wounds gaping due to skin contractility whether cut muscular fibres;
● the nwounds ends have an incision (gradual wound depth underestimation bullock of nher centre to the last from boundary paths own skin and epidermis) and (whether) incision (flesh epidermis damage of linear form);
● dominance of wound nlength over her depth and width. nHowever oeck wound from cutting object can have a considerable depth;
● typical nstrong bleeding, because cut of the vessels, and do not rive, and that’s why do not fall;
● they heal over mostly by first intention and omit the thin linear nscars.
As a rule, the wounds from cutting objects nlocalize on open parts of body: on front surface of the neck, on face, in elbow nbends, on forearms and brushes.
Injuries caused by nchopping objects
The Hewing implements characterize by nconsiderable weight, act from sweep and with force go down on injury object nperpendicularly whether sloping to nsurface: mattock, chopper, , spade, sabre and etc.
By reason of action of hewing objects are generated the wounds, which differ by considerable size and depth, to them inherent signs, ntypical for wounds from sharp objects. By trauma nPeculiarity by hewing objects is ndamage of being subject bone. If under damaged soft cloths not about bone, thesuch advices can be confused with wounds from other sharp objects, specifically n- from cutting.
As a rule, each nwound by axe forwards to safety violations nof being subject bone. Damage of head nbone by hewing objects have its peculiarities. If blade whether linen into bone, nit operates as wedge, separate by her its cheeks into sides. In dependence axe immersion depth bullock ninto bone contradistinguish the, kirve, cuttings.
Injuries caused by nstab objects
The Prickly objects characterize by nlight weight, elongated by Norm and presence of sharp end. Damage by prickly nobjects meet more frequent damages by cutting whether nhewing objects. A Distinctive wounds vainglories peculiarity is the small external wound dimensions and considerable their depth, has a place considerable wound depth dominance nover dimensions of scin hole. This makes their little loud and lustily dangerous for life..
A fracture Form from prickly objects ordinary reproduces transversal crossing of operating nimplement. Bone with fractures, called by prickly objects, attached to necropsy nwithdraval and was nkept in quality of clothe proofs nor to hand investigation down. That namely nbears upon cases, when in wound find nthe objects, which stick in nbone.
Such classification of stab objects is used in modern forensic medicine nvery often (according to A.I.Muhanov, 1964). So, we ndistinguish such stab objects:
nstab objects without edges (nail)
nstab objects with edges (screw);
nstab objects with double-bladed flat n(nife).
A. There are such stab objects without edges: a nneedle, awl, spoke, tenon, nround nail, stylet, rapier, dart and etc., which have non transversal cut a round or oval nform. They operate on cloths by its end, by reason of what is generated a point-wound. In ndependence on implement diameter the wounds frequently are and considerably most, but they thinly are more nthen 0,5-1sm. A Lateral surface of such objects, advancing into depth, separete the ntissue structures, squeezing them on neighbourhood.. Torn shallow vessels lightly trombs and bleeding frequently is insignificant.
B. The stab objects n with edges nare a bayonet, sharpened three- whether ntetrahedral saw, stylet nsuch, screwdriver, , other objects with costal surface. A Body of nsuch objects is grubbed out in pyramid nappearance with sharp end. They can have 3, 4, 8, 6 and more ribs. A Transversal nthem cut has appearance of triangle, nquadrangle, square, heel- whether nhexagon. Damage for counting of ribs (and not borders)action, and by what ribs less, that them corners more nsharp and that greater traumatizing naction they celebrate on cloths.
From action of prickly object with three ribs arise the wounds radiant for form nshallow, because from each ribbing nis generated on one slight tear. Imost cases they do not compose no difficulties for diagnistics.
C. The stab objects with double-bladed flat are such nobjects, which have flat by wedge and handhold. If in blade one edge sharpened, and contrary – in appearance of П–identical nformation, then object is prickle and back. To them belong the different nknives:, hunter, kitchen, composes-ache, both blades nedges are sharpened, then prickly object with two blades.. Among prickly nobjects in judicially-medical practice most frequent damage cause by namely nsuch objects. Going deep plumb into nman body, is counted an implement whether arm ndo not slit (move apart) a cloth, and cut them. A Cut always makes a blade whether blades, and an edge personates auxiliary, as if indicates, paves the way.
Morphological ncharacteristics of self-made wounds
Ordinary law enforcement authorities whether nlaw-court inquire, nand judicially-medical examination can define nby own whether outsider hand the caused damages attached to napplication of sharp objects. Settlement of this question redounds to outcome nto set, was. in concrete case nmurder whether suicide. Damage, drifted to myself to oneself by own hand, not nobligatorily presents by suicide. It may nbe and accidental.
Attached to damages by cutting objects on action of own hand (with view members mutilation of, assault simulation, suicide) indicate such trauma peculiarities whether circumstances:
● ntypical wounds localization on front nbody surface, reachable for own hand: oeck, on front breasts (in heart nallotment )surface, on stomach, on front nforearms surfaces, radiocarpal nand elbow jont.
● ntheir multiplicity, paralel and surface. (
● nsometimes winding of thin handhold of dangerous razor by rag piece, other analogic nobject with view of better ficsation nof blade into hand and brush defense nfrom trauma;
● nrelatively palmar nbrush surface clean from blood, which nheld cutting object (razor).
● nfor wounds from outsider (stranger) hands typical:
● ntransversal are disposed the fingers nwounds and (whether) palms attached to nself-defence, when that, who defends, grabs a knife blade whether dagger and attack with view of to unscrew his nblow, wounds on brushes rear, on. to nback forearms surface, shoulders also arising nattached to attempt. To Be on the defensive;
● nlocalization of one whether a little considerable wounds on any body allotment, but overwhelmingly oeck, face, hands.
FORENSIC EXAMINATION IN nCASES OF FIREARM nINJURIES
Firearm appeared in the middle of XIV century and since that times it is nwidely used in fighting actions.
Firearms
Firearm is the weapon that uses kinetic gunpowder combustion energy to throw out the projectile from the trunk. It is subdivided on artillery nand rifle. A rifle firearm can be grouped as nindividual (or hand) and collective one. The injuries which are caused by explosion of different explosive substances nor devices, belongs to explosive trauma.
Shortly, a firearm is an instrument with which is possible to prople a projectile (missile) by the expansive force of ngases generated as result of combustion of the propellant (powder) in a closed nspace.
Ammunitions
A Bullet is a small projectile in view of steel or leaden ingot of noblong form with sharp or blunt end for firing nfrom rifles, sub-machine-guns, pistols, guns, machine-guns. They are different: long, intermediate and short; sharp nand blunt ended. They are subdivided ousual and special. In shot-guns the leaden and combined bullets are used, such as Jakan, Brenneke, Mayer and others. Bullets from different riflearm differ in mass, for nexample, the weight of bullet for Makarov’s pistol is 6,lg, and nto submachine gun Kalashnikov and SCS carbine is
The ndefeating projectile in hunting cartridges most often is a pellets , that actually are leaden small balls. They can be made by factorial and nhome-made method. In hunter cartridge the ncardboard wad is placed right on gunpowder , then felt wad, to create the best hermetic attach to combustion of gunpowder. nNow wad-containers for pellets from polyethylene are nused. Any wad, found in the place of event or in wound, nis valuable material evidence, that’s why it must be withdraw and given to investigator.
Shot and its mechanism
A Shot is a gunpowder flash in cartridge, that is found icartridge-chamber of firearms, and throw out of bullet (pellets) from trunk under npressure of powder gases, formed by this flash.
The mechanism of formation of bullet nwound is very complicated. A projectile (bullet, fraction) has enormous kinetic energy, which transfers to organism ntissue while entering. Effect of firearm projectile on tissues depends on the nnumber of factors: from bullet or pellets mass, ntheir speed and physical state of tissues. Piercing bullet ability is conditioned by its ” living force” at the moment of nwounding. While increasing the weight of bullet twice the kinetic energy nincreases twice too. At the same time the nincreasing of its speeds twice calls 4 time augmentation of energy. If the mass is constant, a bullet that has greater speed will have greater nenergy.
Entrance and exit holes
A bullet or pellets provokes mostly mechanical traumatic action. A nTypical bullet wound consists of entrance wound, wound channel and exit wound nin the condition of through wound. There are also blind, tangent and direct bullet wounds. While examination of bullet injuries always arises nquestion about direction of shot, about cosituation nof injured and shooting, about direction of nwound channel in man body etc.
The entrance bullet wound (or entrance hole) is small, 6-
It can be of round, or oval form, if bullet enters the body by its maipart perpendicularly to skin surface or under insignificant corner to it. A nRound form of entrance hole is explained by nthe fact that a bullet while entering the body with its front end, makes the hole, that has a form almost similar to ncross-section of round bullet. An oval form of nentrance of bullet wound can be conditioned by immersion of bullet into skin by lateral surface, uneven skicontraction, that displays stronger on the directioof elastic fibers, skin fold wound, change of body nposition, associated with displacement of tissues in wound surrounding areas, etc. Other forms of entrance hole meet rarely.
The other sign, which is very important in recognizing of entrance hole, nis a presence of edging abrasion around it.
The greater kinetic energy of the bullet is, nthe greater tissue defect and the more narrow nedging abrasion are. A width of edging abrasion depends also on size and form of bullet. An edging abrasion is not always well expressed, nspecially on torn big entrance holes.
M. 1. Raisky offered to distinguish also drying nedging, which appears on corpse in 12-24 hours after death by reason of nposthumous skin drying out in the area of its nabrasion on wound edge according damaged epidermis. A drying edging looks like a little wider (0,5-
While penetration of the bullet into body as it rubs the edges of nentrance hole, and different parts that are nalways present on the surface of the bullet stay there. As the result of this there is a presence of darkly-gray or black nnarrow edge on the edge of entrance hole, nwhich is called ring of mud (see picture upper).
A rubbing edge enables not only to distinguish an entrance hole from nexit, but sometimes can be the base for answering the question about succession of shot.
In projection of edge of mud in the entrance bullet wound, there ndisposes one more ring – metallizatioedge which is formed by procrastination of shallow metals nlobules on wound or damage of tissues edge. The edge of entrance bullet wound in typical cases is toothed or smooth, that depends on size of nkinetic energy of bullet: the greater bullet nenergy is, the more equal edges are. Is also depends on a bullet end form. It is a fact, that the sharp bullets form more equal nedge, and rounded or blunted is toothed.
An Exit wound (exit hole) is a nwound, through which a firearm products (bullet, it nparts, pellets) leave a body. It is formed in other way than entrance one. A Bullet, passing over tissues, approaches skin from nwithin and stretches it out in front of noneself in cone appearance. Overcoming tissues resistance, a bullet loses part of kinetic energy. An epidermis oprotrusion top cracks in radial directions and a nskin burst. That is why the form of exit hole is nmost often radiant, crack-viewed or indeterminate, that depends on wound localization and skin elasticity in wound allotment.
Edges of exit hole are toothed, torn with slight tears that go away to nthe sides. The attendant shot factors such as soot, not burnt particles of dust nand etc.
An Exit hole does not have the rubbing, metallization or abrasion edges. nScratching of epidermis sometimes is observed by nexit hole, when skin allotment was pressed nto rock-bottom – to chair back, to wooden wall, sex, sword-belt strap etc.
Additional shot factors and their action
During nthe shot not only the bullet or pellets fly out of nbarrel but also products of nexplosive gunpowder decomposition and other components, which leave the traces on cloth or man body and evecan damage them. These are so called nas additional or concomitant factors of shot. They are: post of constricted air nthat appears in front of bullet, npowder gases, flame, soot, not burnt gunpowder corns, pieces of metal, drops of gun oil, if arm was nsmeared.
They ncome out of a rifled gun only on insignificant ndistance. Exposure of additional shot factors on man’s cloth or body or traces of their action tells that this is nbullet wound, about presence of entrance hole and enables to set shot distance.
Forensic medicine ndistinguishes such distances of a shot: contact, nnear contact, very close, close and distant.
Such dale is accounted for by peculiarities of forensic practice and shot peculiarities from these distances. The Shot fired nfrom all those distances is characterized by some signs. Those signs are very important nin forensic meaning because help to design specific investigator’s questions.
Contact nshot (shot nwithout distance) – when a shot gun is fired with the muzzle in contact with nthe body. Under this a bullet channel is continuation of nbarrel. All of shot factors (projectile, gases, flame, not burnt gunpowder npieces, soot ) come ninto the wound. An imprint of the muzzle (tattooing) is created. It is a nspecific sign of contact shot. It is a damage of the nskin in scratch appearance whether bruise around nentrance of bullet wound hole reproducing constructive peculiarities nof the muzzle.
So, the main forensic appearances of contact shot are:
nLaceration of the nsurface skin
nLaceration of the ndeeper tissues
nFragmentation of bones
nScorching of the skiand hair
nBlackening around the nwound
Imprint of the muzzle
If muzzle arm end is put to part of body, where is subject a thick layer nof soft cloths (seats, thighs, lumbar allotment), theattached to shot closely gases penetrate into wound channel, nconsiderably widening it. An Entrance hole can be usual, nwithout slights tear and exfoliating of skin. But soft cloths (hypodermic base, thewses) considerably situated oconsiderable extent, a wound channel ordinary has nexpansion pairshaped with considerable effusions of nblood into his wall.
Near contact shot – shot from arm, which is disposed nnot perpendicularly to monkey-chatter, and under some ncorner, when to clothes or body leans only part of muzzle cut. Such shot has the shot signs closely and shot from nlustily near distance. Attached to it ndestroying, action celebrates not only bullet whether fraction, but gases and flame. One. part of gases with their composing nelements (by soot, not burnt particles of ndust, metals grains) by on the morrow of bullet penetrate nfrom wound channel, traumatizing a clothes, soft parts whether bone, and where them can be seen attached to research. Other part of gases ndirects outside entrance wound, and soot, the not burnt ngunpowder corns cover clothes allotment whether nskin, disposed on the part of open corner in the shape to oval. A Entrance hole localizes by expertise, by oval edge.
Typical sign of near contact is arched nimpress muzzle of the end of arm from one wound (incomplete stamp-impress) side nin scratch appearance by length 1-
Very close distance is such distance, attached to nshot from which powder gases and flame are still capable to entail damage of clothes whether nto man body. For contemporary hand rifle arm nthis distance compose 5-
A Shot with very close ndistance are characterized by follow signs:
Entry wound is circular
Singed by flame
Surrounded by soot
Cross-like ruptures of the clothes or skin
nBurning around the nwound
Close or Near distance is such distance, when a ntarget is located within the range of gunpowder action but outside the range of nflame. That is why only burnt grains of gun powder and soot (blackening) are nfound around the wound.
Under this an entrance wound has usual description. The soot of shot settles on impediment and can be expressed on distance to
Distant shot. nIn distant shot there aren’t any additional effects around the entry wound. n
In this case additional shot (soot, particles of ndust, metal grains) factors already do not fly so far, and that’s why do not appear. Distant shot for hand rifle arm, as a rule, starts to for nboundary paths
When do not find additional shot traces, then in deductions show, that shot nsigns from near distance not expressed. A Lack of ntraces of near shot not yet bears witness to that nit is done not from near distance. A Shot could be realizable, for example, on the strength of clothes, which is absent, on the strength of nsome gasket, on the strength of doors, which held out nby man body from contrary side and T.i. y such cases traces of near shot remain on cloth, to ngasket whether on doors. A Entrance bullet hole nunder this has the peculiarities incident to it.
n
