Transcript Sławomir Majdanik Firearms injuries Department of the

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
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.
barrel
(cross section)
calibre
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.
m V2
Ek =
Vo = 200-1000 m/s
(even more !)
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)

Entrance wound
(acute angle)

Shot direction
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)
barrel
all gunpowder residue
on the edges or
inside a wound
there may be searing or
burning of wound margins
victim
Gunshot (tight contact)
barrel
reddening
of surrounding margins may
occur due to CO gas
produced by burning
powder (Paltauf sign)
victim
Gunshot (tight contact)
barrel
muzzle impression
(muzzle mark on skin)
victim
Gunshot (tight contact)
barrel
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
victim
Gunshot (loose contact)
barrel
muzzle impression ( - )
gunpowder may escape
from the barrel and
be deposited around
the edges of a wound
victim
Gunshot (close range)
barrel
fouling and stippling
are present
victim
Gunshot (intermediate range)
barrel
<1m
fouling ( - )
stippling
is present
victim
Gunshot (distant range)
>1m
fouling ( - )
stippling ( - )
victim
Shotgun wound /caused by shot/
or
“rat hole” wound
(from 30cm to 1 metre)
contact wounds
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 ?
Most important question is ...
homicide?
suicide?
accident?
A typical hunting accident
“I swear it was a wild boar”
Captive - bolt guns /to dispatch large
animals/
skin
muzzle
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.
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.