Forensic Medicine. Firearm

BASES OF FORENSIC MEDICALBASES OF FORENSIC MEDICAL
TRAUMATOLOGY: firearmTRAUMATOLOGY: firearm

Ballistics is the science of the motion ofBallistics is the science of the motion of
a projectilea projectile..
Exterior ballisticsExterior ballistics is the study of motion ofis the study of motion of
a projectile after it leaves the barrel of aa projectile after it leaves the barrel of a
firearm.firearm.
Interior ballisticsInterior ballistics is the study of physico-is the study of physico-
chemical phenomena within the firearmchemical phenomena within the firearm
from the moment of detonation of primerfrom the moment of detonation of primer
to the time the projectile leaves the barrel.to the time the projectile leaves the barrel.
Terminal ballisticsTerminal ballistics is the study of theis the study of the
effect of impact of a projectile on theeffect of impact of a projectile on the
target (resulting in wound formation -target (resulting in wound formation -
wound ballistics).wound ballistics).

FirearmFirearm
is a specialized device designed tois a specialized device designed to
propel a projectile (shot/bulletpropel a projectile (shot/bullet
missile) by the expansive force ofmissile) by the expansive force of
gases generated as a result ofgases generated as a result of
combustion of the propellantcombustion of the propellant
(powder) at its base in a closed(powder) at its base in a closed
space.space.

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A – the of the trigger releases aA – the of the trigger releases a
pin or hummer whose tip strikespin or hummer whose tip strikes
the percussion cap containingthe percussion cap containing
the sensitive primer at the basethe sensitive primer at the base
of the cartridge.of the cartridge.
B – the primer is detonatedB – the primer is detonated
C – the detonation of the primerC – the detonation of the primer
ignites the main propellantignites the main propellant
charge.charge.
D – the ignition of the mainD – the ignition of the main
propellant charge results in anpropellant charge results in an
explosive formation of hotexplosive formation of hot
gases at very high pressure.gases at very high pressure.
The pressure of the expandingThe pressure of the expanding
gases builds up to an optimumgases builds up to an optimum
value and it forces the missilevalue and it forces the missile
out of the barrel.out of the barrel.

Shotgun cartridgeShotgun cartridge

Classification of Firearms:Classification of Firearms:
FirearmsFirearms are sectioned on:are sectioned on:
artilleryartillery
shootingshooting
Shooting may be 2 types:Shooting may be 2 types:
group (machine guns,group (machine guns,
mortars)mortars)
individual (hand)individual (hand)

Classification of firearms:Classification of firearms:
The individual shooting firearms are sectionedThe individual shooting firearms are sectioned
into follow groups:into follow groups:
1) according to reserving-1) according to reserving-
Battle (automatic devices, carbines, pistols,Battle (automatic devices, carbines, pistols,
rifles);rifles);
Hunting (1-, 2-, 3-, 4-barreled guns);Hunting (1-, 2-, 3-, 4-barreled guns);
Sports (rifles, pistols, revolvers);Sports (rifles, pistols, revolvers);
Special (alarm, construction pistols).Special (alarm, construction pistols).
Atipical: self-made and defect.Atipical: self-made and defect.
2) according to length of a barrel:2) according to length of a barrel:
Long-barrelled (rifles, carbines, machine guns,Long-barrelled (rifles, carbines, machine guns,
pistols - machine guns, hunting rifles);pistols - machine guns, hunting rifles);
Short-barreled (automatic pistols, revolvers).Short-barreled (automatic pistols, revolvers).

Atypical firearmsAtypical firearms

Classification of firearms:Classification of firearms:
3) according to property of a barrel:3) according to property of a barrel:
а) Rifled (rifles, automatic pistols, revolvers);а) Rifled (rifles, automatic pistols, revolvers);
б) Smooth-bored weapons (shotgun);б) Smooth-bored weapons (shotgun);
в) Combined (hunting rifles, sports guns).в) Combined (hunting rifles, sports guns).
4) according to calibre (diameter):4) according to calibre (diameter):
а) Small-calibre (4-6 mm);а) Small-calibre (4-6 mm);
б) Medium-caliber (7-9 mm);б) Medium-caliber (7-9 mm);
в) Large-calibre (more than 9 mm).в) Large-calibre (more than 9 mm).
5) according to the mechanism of a shot:5) according to the mechanism of a shot:
а) Automatic (machine guns);а) Automatic (machine guns);
б) Semi-automatic (pistols, carbines);б) Semi-automatic (pistols, carbines);
в) Not automatic (hunting rifles).в) Not automatic (hunting rifles).

Smooth-bored weapons (shotgun)Smooth-bored weapons (shotgun)
TheThe borebore (sometimes called(sometimes called gauge)gauge) isis
measured by the internal diameter inmeasured by the internal diameter in
inches or by the number of lead balls ofinches or by the number of lead balls of
size almost fitting the barrel, which can besize almost fitting the barrel, which can be
made from one pound of lead.made from one pound of lead.
The most common bore isThe most common bore is a 12a 12 bore.bore.
Thus, the 12 bore gun is one whose boreThus, the 12 bore gun is one whose bore
diameter is that of a ball of lead of such adiameter is that of a ball of lead of such a
size those 12 balls can be made from onesize those 12 balls can be made from one
pound of lead. It is obvious that the greaterpound of lead. It is obvious that the greater
the bore number, the smaller the size of thethe bore number, the smaller the size of the
lead shot, and vice versa.lead shot, and vice versa.

Rifled firearms.Rifled firearms.
In these weapons, the inside of the bore is rifled,In these weapons, the inside of the bore is rifled,
that is, cut longitudinally with a number of spiralthat is, cut longitudinally with a number of spiral
grooves which run parallel to each other, but aregrooves which run parallel to each other, but are
twisted spirally from chamber end to muzzletwisted spirally from chamber end to muzzle
end. This is calledend. This is called rifling.rifling.
The raised portions on the bore are calledThe raised portions on the bore are called landslands
and the lowered ones theand the lowered ones the grooves.grooves.
The distance between opposite fields of riflingThe distance between opposite fields of rifling
grooves in millimeters refers to asgrooves in millimeters refers to as calibrecalibre of theof the
weapon.weapon.
The majority of the battle weapon has calibre fromThe majority of the battle weapon has calibre from
7 up to 9 mm and 4-6 rifling grooves.7 up to 9 mm and 4-6 rifling grooves.

B – calibre of the B – calibre of the
rifled bore.rifled bore.
The distance between The distance between
opposite fields of opposite fields of
rifling grooves in rifling grooves in
millimeters refers to millimeters refers to
as as calibre calibre of the of the
weapon.weapon.

MEDICO-LEGAL QUESTIONSMEDICO-LEGAL QUESTIONS
1.1. Is the injury caused by discharge of firearm?Is the injury caused by discharge of firearm?
2.2. What kind of weapon fired the shot? What kind of weapon fired the shot?
3.3. From what distance and direction was the shot From what distance and direction was the shot
fired?fired?
4.4. When was the firearm discharged? When was the firearm discharged?
5.5. Where an entrance and exit fire apertures?Where an entrance and exit fire apertures?
6.6. What direction of wound canal?What direction of wound canal?
7.7. How many shots have been effected also what How many shots have been effected also what
their sequence, what shot was fatal?their sequence, what shot was fatal?
8.8. Whether there are the signs directing drawing of Whether there are the signs directing drawing of
damage by own hand?damage by own hand?

"alive force" of a bullet"alive force" of a bullet
The flying speed of a bullet of The flying speed of a bullet of
directly proportional its kinetic directly proportional its kinetic
energy ("alive force" of a bullet) energy ("alive force" of a bullet)
also depends on a kind and a also depends on a kind and a
condition of the weapon, quantity condition of the weapon, quantity
and quality of a powder charge and and quality of a powder charge and
distance of a shot. distance of a shot.
Distinguish 4 kinds of action of a Distinguish 4 kinds of action of a
bullet on an organism of the bullet on an organism of the
person:person:

(A) Penetrative -(A) Penetrative -
it is observed at big "alive force" of a it is observed at big "alive force" of a
bullet which beating out a site of a bullet which beating out a site of a
tissue forms defect (“minus – tissue forms defect (“minus –
tissue” - by Райский). tissue” - by Райский).
At attempt to pull together edges of At attempt to pull together edges of
a wound between fingers of arms it a wound between fingers of arms it
is formed a pleat of skin.is formed a pleat of skin.

(B) Cuneiform action of a bullet(B) Cuneiform action of a bullet
- takes place at small "alive force" of a takes place at small "alive force" of a
bullet; bullet;
- the bullet does not punch and moves the bullet does not punch and moves
apart tissues, forming a slit. apart tissues, forming a slit.
- As opposed to penetrative action of a As opposed to penetrative action of a
bullet - cuneiform it is observed at a bullet - cuneiform it is observed at a
exit of a bullet from a body of the exit of a bullet from a body of the
person more often.person more often.

(C) Explosive action of a bullet(C) Explosive action of a bullet
-- can take place at shots of special-purpose can take place at shots of special-purpose
bullets (explosive bullets), at damages of bullets (explosive bullets), at damages of
a bullet covering, and also to cases, when a bullet covering, and also to cases, when
a bullet, having big "alive force", getting in a bullet, having big "alive force", getting in
the self-contained cavities with a liquid the self-contained cavities with a liquid
(the filled stomach), liquid tissues (heart (the filled stomach), liquid tissues (heart
in a condition of a diastole), organs with in a condition of a diastole), organs with
the big percentage of liquids (brain). In the big percentage of liquids (brain). In
that case under action of arising that case under action of arising
hydrodynamical forces (the law of the hydrodynamical forces (the law of the
Pascal) there are extensive destructions Pascal) there are extensive destructions
of these organs.of these organs.

(D) contusion action of a bullet(D) contusion action of a bullet
is displayed at it small "alive force" is displayed at it small "alive force"
that is observed at actions of that is observed at actions of
bullets on exit, at a ricochet. bullets on exit, at a ricochet.
Such bullets usually cause grazes, Such bullets usually cause grazes,
superficial wounds.superficial wounds.

In a bullet wound it is accepted In a bullet wound it is accepted
to distinguish 3 zones:to distinguish 3 zones:
1. 1. A zone of immediate wound canal  A zone of immediate wound canal
(initial destruction).(initial destruction).
2. 2. A zone of a contusion of the tissues  A zone of a contusion of the tissues
being walls of the canal, width from being walls of the canal, width from
several mm up to 1-2 cm.several mm up to 1-2 cm.
3. 3. A zone of molecular shake of the  A zone of molecular shake of the
tissue propagated sometimes on 4-5 cm tissue propagated sometimes on 4-5 cm
and more. and more.

N. I. Pirogov (I8I0-I88I) -N. I. Pirogov (I8I0-I88I) -
the Russian surgeon, on the basis of the bigthe Russian surgeon, on the basis of the big
practical experience in treatment of firepractical experience in treatment of fire
damages for the first time has describeddamages for the first time has described
changes which are observed in the aeries ofchanges which are observed in the aeries of
entrance and exit fire wounds that matters forentrance and exit fire wounds that matters for
forensic medicine presently:forensic medicine presently:
1. About absence of differences in size of1. About absence of differences in size of
entrance and exit gunshot wounds. (1875)entrance and exit gunshot wounds. (1875)
2.2. About defect of a tissue around an entranceAbout defect of a tissue around an entrance
gunshot wound. (1859)gunshot wound. (1859)
3. About abrasion collar around an entrance3. About abrasion collar around an entrance
gunshot wound. (1865)gunshot wound. (1865)

Distinguish 3 kinds Distinguish 3 kinds
of gunshot wounds:of gunshot wounds:
tangential wound,tangential wound,
nonperforating (blind),nonperforating (blind),
through.through.

Penetrative action of a bullet on a skin.Penetrative action of a bullet on a skin.
Formation of Defect "minus - tissue“, Formation of Defect "minus - tissue“,
Abrasion Collar and “Grease or Dirt Collar"Abrasion Collar and “Grease or Dirt Collar"

Entrance Wounds from Entrance Wounds from
ShotgunsShotguns

(A) abraded collar or contusion ring;(A) abraded collar or contusion ring;
(B) grease/dirt collar;(B) grease/dirt collar;
(C) powder distribution (tattoo marks);(C) powder distribution (tattoo marks);
(D) blackening(D) blackening

wound canalwound canal
The path, which has passed aThe path, which has passed a
shell in a body, has the nameshell in a body, has the name
the wound canalthe wound canal..

Wound canals can be divided on direct andWound canals can be divided on direct and
indirect, intermittent and continuous.indirect, intermittent and continuous.
TheThe directdirect continuous canal passes through allcontinuous canal passes through all
organs on one line.organs on one line.
InterruptedInterrupted canal it is formed due tocanal it is formed due to
displacement of organs under the attitude todisplacement of organs under the attitude to
each other.each other.
IndirectIndirect canals are formed due to change ofcanals are formed due to change of
bullet’s flying as a result of collision of abullet’s flying as a result of collision of a
bullet with a bone, more dense tissues, etc.bullet with a bone, more dense tissues, etc.
InterruptedInterrupted indirectindirect canals are at hit of acanals are at hit of a
bullet in a cavity of a backbone, an intestine,bullet in a cavity of a backbone, an intestine,
etc. in which it can pass any distance, andetc. in which it can pass any distance, and
then exit in the other place.then exit in the other place.

In that case under action of arisingIn that case under action of arising
hydrodynamical forces (the law of the Pascal)hydrodynamical forces (the law of the Pascal)
there are extensive destructions of thesethere are extensive destructions of these
organs.organs.

Contact shot on the head.Contact shot on the head.
The gases from the explosion expandThe gases from the explosion expand
between the scalp and scull resulting in abetween the scalp and scull resulting in a
bursting effect and ragged entrancebursting effect and ragged entrance
wound.wound.

For flat bones (the skull, a scapula,For flat bones (the skull, a scapula,
flanks of ileal bones, and a sternum) theflanks of ileal bones, and a sternum) the
most typical is a foramen fracturemost typical is a foramen fracture..

Wound canalWound canal researchresearch aa level-by-levellevel-by-level
methodmethod during autopsy.during autopsy.
Thus studyThus study
character and frame of damages of tissuescharacter and frame of damages of tissues
and organs,and organs,
a direction of the canal,a direction of the canal,
its contents;its contents;
define deposition of additional factors,define deposition of additional factors,
parts of a tissue of clothes and otherparts of a tissue of clothes and other
foreign impurities;foreign impurities;
conduct search of a fire shell and theconduct search of a fire shell and the
secondary shells (fragments of bones, asecondary shells (fragments of bones, a
part of the solid subjects available outside)part of the solid subjects available outside)

Shavinjy’s phenomenonShavinjy’s phenomenon
In case of damage to flat bones it isIn case of damage to flat bones it is
necessary to take intonecessary to take into
consideration the course ofconsideration the course of
fissures. The fissures, which werefissures. The fissures, which were
produced by the next shot, do notproduced by the next shot, do not
cross those ones, which werecross those ones, which were
produced by the previous shotproduced by the previous shot

EXIT WOUNDEXIT WOUND
The edges are freeThe edges are free
from signs of:from signs of:
defect "minus -defect "minus -
tissue",tissue",
burning,burning,
blackening orblackening or
tattooing,tattooing,
no contusion orno contusion or
abrasion collar.abrasion collar.

The variation in the shape and large size ofThe variation in the shape and large size of
the exit wound are due to:the exit wound are due to:
(1) The bullet tumbles in the body and fails to(1) The bullet tumbles in the body and fails to
exit nose end first.exit nose end first.
(2) The bullet is deformed.(2) The bullet is deformed.
(3) The bullet breaks up in the tissues and exits(3) The bullet breaks up in the tissues and exits
as several pieces.as several pieces.
(4) Fragments of the bone may be blown out of(4) Fragments of the bone may be blown out of
the body with the bullet.the body with the bullet.
(5) The unsupported skin at the exit tends to(5) The unsupported skin at the exit tends to
tear and break into pieces. Exit wounds oftear and break into pieces. Exit wounds of
the head are usually star-shaped, resemblingthe head are usually star-shaped, resembling
contact entrance wound.contact entrance wound.

distance of a shotdistance of a shot
TheThe distance of a shotdistance of a shot is understood asis understood as
distance between muzzle and a surfacedistance between muzzle and a surface
of an injured body.of an injured body.
In forensic medicine distinguish 3In forensic medicine distinguish 3
distances:distances:
••                                            contact shot,contact shot,
••                                            close shot,close shot,
••                                            distant shot.distant shot.

Additional factors of a shot and theirAdditional factors of a shot and their
action on a skin around the entranceaction on a skin around the entrance
woundwound
Flame: 3-5 cm - burningFlame: 3-5 cm - burning
Powder gases: 15-20 cm - formation ofPowder gases: 15-20 cm - formation of
parchment spotsparchment spots
Soot black: 20-40 cm - blackeningSoot black: 20-40 cm - blackening
Unburnt and partially burnt powderUnburnt and partially burnt powder
grains; small metallic particles: up to 1grains; small metallic particles: up to 1
meter - tattooingmeter - tattooing

Contact distance (blackening).Contact distance (blackening).

Clothing should be removed with careClothing should be removed with care
keeping in mind the possibility of findingkeeping in mind the possibility of finding
bullets/pellets in them.bullets/pellets in them.

Entrance wounds.Entrance wounds.
Close distanceClose distance

Entrance wounds.Entrance wounds.
Close distance (blackening).Close distance (blackening).

Distant Shot:Distant Shot:
The entrance woundThe entrance wound

phenomenon by Vinogradovphenomenon by Vinogradov
In some cases at a shot from a distantIn some cases at a shot from a distant
distance it is possible to find outdistance it is possible to find out
deposition of a soot black on inner layersdeposition of a soot black on inner layers
of clothes or around of a skin at itsof clothes or around of a skin at its
absence on surface layers of clothes.absence on surface layers of clothes.
The basic conditions for such deposition of aThe basic conditions for such deposition of a
soot black issoot black is
presence of several traces of clothes, whichpresence of several traces of clothes, which
be distant from each other up to 1-1,5 cm.be distant from each other up to 1-1,5 cm.
and the big flying speed of a bullet (fromand the big flying speed of a bullet (from
above 500 m/sec.).above 500 m/sec.).

Cause of death:Cause of death:
Haemorrhage and injury to vital organs leadingHaemorrhage and injury to vital organs leading
to shock are the common causes of death.to shock are the common causes of death.
In abdominal wounds, infection is anotherIn abdominal wounds, infection is another
common immediate cause of death.common immediate cause of death.
Complications like peritonitis develop due toComplications like peritonitis develop due to
leakage of contents from the gastrointestinalleakage of contents from the gastrointestinal
tract and lead to death in due course.tract and lead to death in due course.
Pneumonia develops frequently in headPneumonia develops frequently in head
injuries with prolonged unconsciousness.injuries with prolonged unconsciousness.
Hypostatic pneumonia develops in elderlyHypostatic pneumonia develops in elderly
patients who are bed-ridden even for a fewpatients who are bed-ridden even for a few
days.days.

BOMB EXPLOSION WOUNDSBOMB EXPLOSION WOUNDS
A bomb is a container filled with anA bomb is a container filled with an
explosive mixture and missiles, which isexplosive mixture and missiles, which is
fired either by a detonator or a fuse. Whenfired either by a detonator or a fuse. When
an explosion occurs, the explosivean explosion occurs, the explosive
material produces a large volume of gasmaterial produces a large volume of gas
and releases very large amount of energy.and releases very large amount of energy.
Pressures of up to thousand tons per sq.Pressures of up to thousand tons per sq.
inch can be produced.inch can be produced.

A person can be injured by an explosion in aA person can be injured by an explosion in a
number of ways.number of ways.
(1) Disruptive Effects.(1) Disruptive Effects.
(2)Burns.(2)Burns.
(3) Air Blast.(3) Air Blast.
(4) Flying Missiles.(4) Flying Missiles.
(5) Falling Masonry.(5) Falling Masonry.
(6) Fumes.(6) Fumes.

Forensic Medicine. Firearm

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