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Sławomir Majdanik Firearm injuries Department of the Forensic Medicine Pomeranian Academy of Medicine of Szczecin. Definition many kinds of weapons may cause firearm injury: shotguns /used by hunters/ handguns (pistols or revolvers) rifles home - made guns / `country guns`/ air rifles
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Sławomir MajdanikFirearm injuriesDepartment of the Forensic Medicine Pomeranian Academy of Medicine of Szczecin
Definition many kinds of weapons may cause firearm injury: shotguns /used by hunters/ handguns (pistols or revolvers) rifles home - made guns / `country guns`/ air rifles sports guns
Definition Rarely firearm injuries are caused using other kinds of objects: projectiles and their fragments (artillery shells, mortars) captive - bolt guns industrial stud-guns alarm guns /tracer shells/
Gun muzzle barrel trigger gunlock cock
Cartridge Projectile Gunpowder Cartridge case Primer
Shotgun ammunition Wad Gunpowder and shot Cardboard or plastic cylinder Metal base including primer
Calibre 7.62 mm and 9 mm are most frequent calibres in Poland. calibre barrel (cross section)
Basic factors affect nature of a gunshot wound type of weapon missile velocity nature of projectile range of discharge angle of discharge
Why firearms injuries are often fatal ? Because of significant kinetic energy of the bullet. Vo = 200-1000 m/s (even more !) m V2 Ek= 2
Gunshot injuries I. Gunshot injury penetrate through the head (or leg, arm, neck, trunk ...) a/ entrance wound b/ canal of the shot c/ exit wound
Gunshot injuries II. “blind” shots - bullet is lodged in the victim`s body a/ entrance wound b/ canal of the shot c/ bullet in the body
“Migrating bullet” bullet when lodged in the vessel may move /up or down the blood flow/ in the victim`s body
“Migrating bullet” bullet when lodged in a cavity may move /following the gravitation force/ in the victim`s body
Gunshot injuries III. Diagonal gunshot injury /wound or abrasion/
Gunshot injuries IV. Ricochet (bullet changes trajectory) Nevertheless non typical serious injuries may occur lower velocity of the bullet
Gunpowder comes out the muzzle in two forms: Completely burned gunpowder, called “soot” or “fouling”, can be washed off the skin. Particles of burned and unburned powder can become embedded in the skin or bounce off and abrade the skin. The marks on the skin are called “tattooing” or “stippling”.
Analysis of the gunpowder traces A. microscope determination (including electron microscopy) B. chemical determination 1. Wellenstein-Kober reaction (green-blue tint) 2. “parch” reaction /in high temp./ 3. Griess&Illosvay reaction (pink tint)
Shot direction Entrance wound (right angle) Central defect Soiled area (lubricant & soot & metal fragments) Rim of abrasion [width=1-3mm] (effect of the shock wave) Stippling/tattooing & soot/fouling area (burned gunpowder and gunpowder particles)
Shot direction Entrance wound (acute angle)
Canal of the wound Fragments of clothing Fragments of bullet/shot Fragments of bone /other tissue/
Exit wound Central defect soiled area (none) rim of abrasion (none) gunpowder and its traces (none)
Gunshot (tight contact and loose contact) tight contact skin barrel muzzle loose contact
Gunshot (tight contact) all gunpowder residue on the edges or inside a wound there may be searing or burning of wound margins barrel victim
Gunshot (tight contact) reddening of surrounding margins may occur due to CO gas produced by burning powder (Paltauf sign) barrel victim
Gunshot (tight contact) muzzle impression (muzzle mark on skin) barrel victim
Gunshot (tight contact) There is often tearing of the skin around the entrance wound (specially in head wounds) because of pressure build-up and blow-back of the skin toward the muzzle barrel victim
Gunshot (loose contact) muzzle impression ( - ) gunpowder may escape from the barrel and be deposited around the edges of a wound barrel victim
Gunshot (close range) fouling and stippling are present barrel victim
Gunshot (intermediate range) fouling ( - ) stippling is present barrel < 1 m victim
Gunshot (distant range) fouling ( - ) stippling ( - ) > 1 m victim
Shotgun wound /caused by shot/ or contact wounds “rat hole” wound (from 30cm to 1 metre)
Shotgun wound /caused by shot/ Satellite pellet holes (appearing at the distance of over 1 metre) Spread of shot increases, central hole diminishes Uniform spread with no central hole (appearing at the distance of over 10 metres)
Scene 1. The scene must be examined for bullets and cartridges. 2. Localisation of the body and the gun must be considered. 3. Traces on the wearing and victims hands must be protected !
Autopsy examination in the case of gunshot 1. Inspection of the victim`s clothing (gun powder traces, damage) 2. Localisation and inspection of the entrance/exit wound 3. Inspection of the canal of the wound 4. Finding the bullet
Commonly asked question I. How close was the victim to the gun when it was fired ? II. What was the the trajectory in the body ? (where is the entrance/exit wound ?) III What was the calibre /kind/ of the gun ? IV. What was the sequence of the gunshot ?
A typical hunting accident “I swear it was a wild boar”
Captive - bolt guns /to dispatch large animals/ Metal rod is propelled for about 5 centimetres from the muzzle. skin Captive bolt inflicts a clean, penetrating injury, which can be mistaken with stab-like injury. muzzle
Industrial “stud-guns” Specific piston acts as a hammer on the metal pin or stud. skin/wall muzzle
Rubber and plastic bullets To disperse riot Velocity about 250 kph Effective range 50-70m
Death from explosion Both civilian and military circumstances
Death from explosion - mechanisms a/ blast effect b/ impact of projectiles originating from the explosives device c/ impact from surrounding objects and debris impelled by the explosion d/ burns from hot gas and incandescent objects
Death from explosion - injuries “Peppering” by numerous small missiles causing lacerations and bruises. Burning. A bomb can totally fragment the body and scatter unidentifiable pieces over a large area.