Definition many kinds of weapons may cause firearm injury: shotguns /used by hunters
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Transcript of Definition many kinds of weapons may cause firearm injury: shotguns /used by hunters
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)rifleshome - made guns / `country guns`/air riflessports 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/
Basic factors affect nature of a gunshot wound
type of weapon missile velocity nature of projectile
range of dischargeangle of discharge
Why firearms injuries are often fatal ?
Because of significant kinetic energy of the bullet.
Vo = 200-1000 m/s (even more !)
Ek = m V2
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
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 determination1. Wellenstein-Kober reaction (green-blue tint)2. “parch” reaction /in high temp./3. Griess&Illosvay reaction (pink tint)
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
Gunshot (tight contact)
all gunpowder residueon the edges or inside a wound
there may be searing or burning of wound margins
barrel
victim
Gunshot (tight contact)
reddeningof surrounding margins may
occur due to CO gas produced by burning powder (Paltauf sign)
barrel
victim
Gunshot (tight contact)
There is often tearing of the skin around the entrance wound (specially in head
wounds) because of pressurebuild-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
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 atthe 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 ?
Captive - bolt guns /to dispatch large animals/
Metal rod is propelled for about 5 centimetres from the muzzle.
Captive bolt inflicts a clean, penetrating injury, which can be
mistaken with stab-like injury.
skin
muzzle
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