dr. elias bin akber's forensic medicine presentation

FIREARM INJURIE FIREARM INJURIESS

• Forensic Ball Forensic Ballii :stic:stic

This is the science dealing with the This is the science dealing with the

, investigation of firearms amunition , investigation of firearms amunition

and the problems arising from their and the problems arising from their

.use.use

FIREARMSFIREARMS

DefinDefinii :tion:tion

This is an instrument which discharges This is an instrument which discharges a missile by the expansive forces of a missile by the expansive forces of

ggaa ses produced by burning of explosive ses produced by burning of explosive.substances.substances

:CLASSIFICATION OF FIREARMS :CLASSIFICATION OF FIREARMS

:Depending on the bore or inner surface of the barrel :Depending on the bore or inner surface of the barrel

1.1. / .Rifled firearms Guns / .Rifled firearms Guns

2.2. / .Smooth bored firearms Shotguns / .Smooth bored firearms Shotguns

: , GUNS DEF EXAMPLES & CLASSIFICATION : , GUNS DEF EXAMPLES & CLASSIFICATION::

: .Guns Thse are firearms weapons which confines missiles or bullet : .Guns Thse are firearms weapons which confines missiles or bullet

: , 3 3, , , , .Example Airgun not Pistol Rivolver Automatic Pistol Machinegun : , 3 3, , , , .Example Airgun not Pistol Rivolver Automatic Pistol Machinegun

:Classification :Classification

1.1. – 30 / ( )Low Velocity up to m sec Revolver – 30 / ( )Low Velocity up to m sec Revolver

2.2. – 360-750 / ( )Medium Velocity m sec Pistol – 360-750 / ( )Medium Velocity m sec Pistol

3.3. – 900 / (3 3)High Velocity m sec not – 900 / (3 3)High Velocity m sec not

SMOOTH BORED FIREARMS:SMOOTH BORED FIREARMS:• These are firearms weapons which can fire missile in the form of multiple

pellets at a time.

Classification :

1.Single barrel.

2.Double barrel.

3.Slide action.

4.Liver action.

5.Bolt action. A) Overbolt action, B) Underbolt action.

6.Pump action.

7.Semi automatic.

8.Automatic.

BULLET & PELLETBULLET & PELLET

Bullet :Bullet :

This is the projectile from a rifled firearm.This is the projectile from a rifled firearm.

Pellet :Pellet :

This is the projectile from a smooth bored firearm / shot gun.This is the projectile from a smooth bored firearm / shot gun.

RIFLING RIFLING

Definition :Definition :

Grooving on the inner surface of the barrel of a firearm is called Rifling.Grooving on the inner surface of the barrel of a firearm is called Rifling.

There are spiral grooves and elevated portions along the length of the barrel. There are spiral grooves and elevated portions along the length of the barrel.

The spiral grooves out longitudinally in the inner surface of the barrel.The spiral grooves out longitudinally in the inner surface of the barrel.

Rifling may be clockwise / ante-clockwise.Rifling may be clockwise / ante-clockwise.

Its number varies from 2-20. (most commonly 6)Its number varies from 2-20. (most commonly 6)

MEDICOLEGAL IMPORTANCE OF RIFLING :MEDICOLEGAL IMPORTANCE OF RIFLING :

1.1. It gives the bullet a spinning effect and it spins around its long axis.It gives the bullet a spinning effect and it spins around its long axis.

2.2. It gives the bullet a greater power of penetration.It gives the bullet a greater power of penetration.

3.3. It prevents the unsteady movement of the bullet when it travels in the air.It prevents the unsteady movement of the bullet when it travels in the air.

4.4. It maintains the straight accuracy.It maintains the straight accuracy.

5.5. It helps to identify the firearm weapon.It helps to identify the firearm weapon.

CHOKINGCHOKING

Definition :Definition :

Narrowing of the barrel of a shot gun at distal 7-10 cm is called Choking.Narrowing of the barrel of a shot gun at distal 7-10 cm is called Choking.

Classification :Classification :

1.1.Full Choke.Full Choke.

2.2.Three quarter choke.Three quarter choke.

3.3.Half chokeHalf choke

4.4.Quarter choke.Quarter choke.

5.5.Improved cylinder.Improved cylinder.

DEGREE OF CHOKINGDEGREE OF CHOKING

Degree of Choking Degree of constriction

1. Full choke 40/1000th of an inch

2. Three quarter choke 30/1000th of an inch

3. Half choke 20/1000th of an inch.

4. Quarter choke 10/1000th of an inch.

5. Improved cylinder 3-5/1000th of an inch

IMPORTANCE OF CHOKINGIMPORTANCE OF CHOKING

1.1. It lessens the rate of spread of shot after it leaves the muzzle.It lessens the rate of spread of shot after it leaves the muzzle.

2.2. It increases the explosive force and velocity.It increases the explosive force and velocity.

3.3. Thus by choking the effective range and penetration capacity of the pellets Thus by choking the effective range and penetration capacity of the pellets

is increased.is increased.

PRIMER/ PRIMING MIXTUREPRIMER/ PRIMING MIXTURE

Definition :Definition :

This is the percussion cap at the base of the cartridge containing a small This is the percussion cap at the base of the cartridge containing a small amount of sensitive, detonating composition.amount of sensitive, detonating composition.

Composition :Composition :

1.1.Potassium Chlorate.Potassium Chlorate.

2.2.Antimony Sulphide.Antimony Sulphide.

3.3.Mercury Fulminate.Mercury Fulminate.

GUN POWDERGUN POWDER

Definition :Definition :

This is a mixture of explosive substances which propels the bullet forward by the This is a mixture of explosive substances which propels the bullet forward by the enormous pressure created as a result of expansion of gases by its explosion.enormous pressure created as a result of expansion of gases by its explosion.

Classification :Classification :1.1.Black Powder.Black Powder.

2.2.Smokeless Powder.Smokeless Powder.

3.3.Semi-smokeless Powder.Semi-smokeless Powder.

GUN POWDERGUN POWDER

COMPOSITION OF GUN POWDER COMPOSITION OF GUN POWDER Black Powder:Black Powder:

1.1.Potassium Nitrate- 75%Potassium Nitrate- 75%

2.2.Charcoal- 15% Sulphur- 10%Charcoal- 15% Sulphur- 10%

3.3.Sulphur- 10%Sulphur- 10%

Smokeless Powder:Smokeless Powder:

1.1.Nitrocellulose (Gun Cotton)Nitrocellulose (Gun Cotton)

OrOr

2. Nritrocellulose + Nirtoglycerine (Double Base)2. Nritrocellulose + Nirtoglycerine (Double Base)

Semi Smokeless Powder:Semi Smokeless Powder:

1.Black Powder-80%1.Black Powder-80%

2. Smokeless Powder-20%2. Smokeless Powder-20%

CHARACTERISTICS OF SUICIDAL PISTIOL CHARACTERISTICS OF SUICIDAL PISTIOL SHOT:SHOT:

1.1. Number of wound- Usually 1Number of wound- Usually 1

2.2. Attempt of Suicide- Previously attemptedAttempt of Suicide- Previously attempted

3.3. Contact shot woundContact shot wound

4.4. Sites of wound Rt Temporal (60%), Lt TemporalSites of wound Rt Temporal (60%), Lt Temporal

Centre of forehead, EyeCentre of forehead, Eye

Left side of the chest, EpigastriumLeft side of the chest, Epigastrium

Mouth, ThroatMouth, Throat

5. Weapon- May be found by the side ( Beside table, floor) or at hand. 5. Weapon- May be found by the side ( Beside table, floor) or at hand.

6. Attitude- Last few days the person was not normal6. Attitude- Last few days the person was not normal

7. Direction- Upwards, forwards/ backwards. 7. Direction- Upwards, forwards/ backwards.

SUICIDAL PISTOL SHOT WOUNDSUICIDAL PISTOL SHOT WOUND

CHARACTERISTICS OF SHOTGUN CHARACTERISTICS OF SHOTGUN WOUNDSWOUNDS

A. Contact shot:A. Contact shot:

1.1.Single, round or oval.Single, round or oval.

2.2.Size – equal to the bore of the weapon.Size – equal to the bore of the weapon.

3.3.Unburnt powder may go into the wound and cause haemorrhage.Unburnt powder may go into the wound and cause haemorrhage.

4.4.The margin of the wound will be contused.The margin of the wound will be contused.

5.5.Muzzle impression is seen, if the contact is tight.Muzzle impression is seen, if the contact is tight.

SHOT GUN WOUNDSSHOT GUN WOUNDS

CHARACTERISTICS OF SHOTGUN CHARACTERISTICS OF SHOTGUN WOUNDS: CONT:WOUNDS: CONT:

B. Close range (up to 1 meter)B. Close range (up to 1 meter)

•Within a distance of about 30 cm, tissues surrounding the wound are singed Within a distance of about 30 cm, tissues surrounding the wound are singed

by flame, blackened by smoke(carbon sut) and tattooed by unburnt/ partially by flame, blackened by smoke(carbon sut) and tattooed by unburnt/ partially

burnt gun powder granules.burnt gun powder granules.

•Tissues within and around the wound may be cherry red in color due to Tissues within and around the wound may be cherry red in color due to

absorption of CO.absorption of CO.

CHARACTERISTICS OF SHOTGUN CHARACTERISTICS OF SHOTGUN WOUNDS : CONT :WOUNDS : CONT :

C. Long Range :C. Long Range :

At a distance of 4 meters, shots spread widely and enter the At a distance of 4 meters, shots spread widely and enter the body as individual pellets and produce separate opening in an body as individual pellets and produce separate opening in an area of 10-15 cm in diameter. They are present usually up to area of 10-15 cm in diameter. They are present usually up to 5 meters.5 meters.

The spread of pellets from a fully choked bore is as follows :The spread of pellets from a fully choked bore is as follows :

•10 meters 10 meters 25 cm 25 cm

•15 meters 15 meters 35 cm 35 cm

•20 meters 20 meters 45 cm. 45 cm.

•30 meters 30 meters 75 cm. 75 cm.

DIFFERENCES BETWEEN THE ENTRY AND DIFFERENCES BETWEEN THE ENTRY AND EXIT WOUNDSEXIT WOUNDS

Traits Entry wound Exit Wound

1. Size Smaller when near, larger when distant

Larger when near, smaller when distant.

2. Margin. Inverted Everted.

3. Singeing, burning, blackening & Tattooing

Present Absent

4. Abrasion, bruise & Grease collar

Present Absent

5. Haemorrhage Less More

6. Protrusion of fat Absent Present

DIFFERENCES BETWEEN THE ENTRY AND DIFFERENCES BETWEEN THE ENTRY AND EXIT WOUNDSEXIT WOUNDS

Traits Entry Wound Exit Wound

7. Tissues within and around the wound

May be cherry red due to CO

No colour change

8. Foreign fabrics of clothes Enters into the wound Nothing such

9. Metallic ring shadow on X-ray

Present Absent

10. Muzzle impression Present in case of contact shot

Absent

11. Bursting Effect Present in case of contact shot

Absent

PICTURES SHOWING ENTRY & EXIT PICTURES SHOWING ENTRY & EXIT WOUNDSWOUNDS

DIFFERENCE BETWEEN SUICIDAL AND DIFFERENCE BETWEEN SUICIDAL AND HOMICIDAL GUN SHOT WOUNDHOMICIDAL GUN SHOT WOUND

Traits Suicidal Homicidal

1. Site of entry wound Head or Heart Any Where

2. Shot distance Contact or close shot Any range

3. Direction Upwards, forwards or backwards

Usually upward

4. Number of wounds Usually one One to many

5. Hand Pressing trigger Gun powder residue present Absent

DIFFERENCE BETWEEN SICIDAL AND DIFFERENCE BETWEEN SICIDAL AND HOMOCIDAL GUN SHOT WOUNDHOMOCIDAL GUN SHOT WOUND

Traits Suicidal Homicidal

6. Position of the weapon Found the scene Not found the scene

7. Scene of crime Usually one house Any place

8. Sex of the victim Usually male Any sex

9. Motive Insanity Incurable illnessFinancial lossUnbearable mental pressure

Gang fudes,Enmity,Revenge,Robbery.

RICOCHET BULLET & YAWNING BULLETRICOCHET BULLET & YAWNING BULLET

Richochet Bullet:Richochet Bullet:

This is the bullet which before striking the object aimed This is the bullet which before striking the object aimed

at, strikes intervening object first and then after at, strikes intervening object first and then after

ricocheting and re-bouncing from this hits the object.ricocheting and re-bouncing from this hits the object.

Yawning Bullet: Yawning Bullet:

This is the bullet that travels in an irregular fashion This is the bullet that travels in an irregular fashion

instead of travelling nose on is called Yawning Bulletinstead of travelling nose on is called Yawning Bullet

TUMBLING BULLET & INCENDIARY BULLET TUMBLING BULLET & INCENDIARY BULLET

Tumbling Bullet :Tumbling Bullet :

This is the bullet which rotates end to end during its This is the bullet which rotates end to end during its

motion is called Tumbling Bullet.motion is called Tumbling Bullet.

Incendiary Bullet :Incendiary Bullet :

This is the bullet which contains phosphorus, so that it This is the bullet which contains phosphorus, so that it

catches fire on hitting the target is called Incendiary catches fire on hitting the target is called Incendiary

BulletBullet

INCENDIARY BULLETINCENDIARY BULLET

EXPRESS BULLET & TANDEM BULLETEXPRESS BULLET & TANDEM BULLET

Express Bullet or Hollow Point: Express Bullet or Hollow Point:

This is the bullet with a hole in the point is called Hollow point or expressed bullet.This is the bullet with a hole in the point is called Hollow point or expressed bullet.

Tandem Bullet/ Piggyback Bullet: Tandem Bullet/ Piggyback Bullet:

Due to defect in the weapon or due to faulty ammunition or if the firearm is unused Due to defect in the weapon or due to faulty ammunition or if the firearm is unused for several years --- When such a weapon is fired, the bullet may fail to come out for several years --- When such a weapon is fired, the bullet may fail to come out from the muzzle. When it is fired again the second bullet may go off carrying the from the muzzle. When it is fired again the second bullet may go off carrying the lodged bullet with it and both the bullets may enter the body through the same lodged bullet with it and both the bullets may enter the body through the same entrance wound. entrance wound.

This is called Tandem Bullet or Piggyback Bullet. This is called Tandem Bullet or Piggyback Bullet.

SOUVENIR BULLET & EXHIBIT BULLET SOUVENIR BULLET & EXHIBIT BULLET

Souvenir Bullet:Souvenir Bullet:

This is the bullet which is present in the body for a long period of time. There will be no This is the bullet which is present in the body for a long period of time. There will be no

fresh bleeding in the surrounding area. A dense fibrous tissue capsule usually fresh bleeding in the surrounding area. A dense fibrous tissue capsule usually

surrounds it.surrounds it.

Lead poisoning may occur due to absorption of Lead.Lead poisoning may occur due to absorption of Lead.

Exhibit Bullet or Crime Bullet: Exhibit Bullet or Crime Bullet:

The bullet found in the body after postmortem examination is sent to the Police Station The bullet found in the body after postmortem examination is sent to the Police Station

and then to the Court for further trail of the case is called Exhibit Bullet or Crime Bullet.and then to the Court for further trail of the case is called Exhibit Bullet or Crime Bullet.

TEST BULLET, DUM DUM BULLET & TEST BULLET, DUM DUM BULLET & FRANGIBLE BULLETFRANGIBLE BULLET

Test Bullet: Test Bullet:

The exhibit bullet is compared under a comparison microscope with one fired bullet from the The exhibit bullet is compared under a comparison microscope with one fired bullet from the suspected weapon is called Test Bullet.suspected weapon is called Test Bullet.

Dum dum Bullet: Dum dum Bullet:

Dum dum bullets are hollow at their nose. These bullets split when they strike the body, Dum dum bullets are hollow at their nose. These bullets split when they strike the body, causing disproportionately greater damage to the affected part. causing disproportionately greater damage to the affected part.

Frangible Bullet: Frangible Bullet:

These bullets are made of mostly by Lead or Iron and are designed to fragment upon impact. These bullets are made of mostly by Lead or Iron and are designed to fragment upon impact.

RUBBER BULLETRUBBER BULLET

Rubber Bullet/ Plastic Bullet/ Baton Round: Rubber Bullet/ Plastic Bullet/ Baton Round:

Rubber Bullet is a solid cylinder of Polyvinylchloride (PVC) , 38 mm in diameter, Rubber Bullet is a solid cylinder of Polyvinylchloride (PVC) , 38 mm in diameter,

10 cm long and weighs 135 gm. They cause abrasion and bruise. They do not 10 cm long and weighs 135 gm. They cause abrasion and bruise. They do not

cause punctured wounds except when fired from under 20 meters range. They cause punctured wounds except when fired from under 20 meters range. They

are used by the Police for riot control. are used by the Police for riot control.

RUBBER BULLETRUBBER BULLET

RUBBER BULLETRUBBER BULLET

DERMAL NITRATE TESTDERMAL NITRATE TEST

Synonyms: Synonyms:

a)a)Paraffin TestParaffin Test

b)b)Diphenylamine TestDiphenylamine Test

Historical Background: Historical Background:

This test was introduced in the U.S.A in 1993 by Teodoro Gonzalez of the Criminal This test was introduced in the U.S.A in 1993 by Teodoro Gonzalez of the Criminal Identification Laboratory at Mexico City Police Headquarters.Identification Laboratory at Mexico City Police Headquarters.

This test detects gun powder residues.This test detects gun powder residues.

(Nitrites and Nitrates). (Nitrites and Nitrates).

DERMAL NITRATE TESTDERMAL NITRATE TEST

Procedure:Procedure:

In this test, the hands are coated with a layer of Paraffin. After cooling, the casts In this test, the hands are coated with a layer of Paraffin. After cooling, the casts are removed & treated with an acid solution of Diphenylamine to detect gun are removed & treated with an acid solution of Diphenylamine to detect gun powder residue.powder residue.

Interpretation: Interpretation:

1.1.Blue flacks in the paraffin Blue flacks in the paraffin +ve test. +ve test.

2.2.However, false positive results were also obtained on the hands of the individual However, false positive results were also obtained on the hands of the individual who had not fired the weapon because and Nitrites in the atmosphere. who had not fired the weapon because and Nitrites in the atmosphere.

Therefore, this test is absolete now-a-day. Therefore, this test is absolete now-a-day.

DERMAL NITRATE TESTDERMAL NITRATE TEST

KENNEDY PHENOMENON: KENNEDY PHENOMENON:

Surgical alteration or suturing of gun shot wound creates problems. The Surgical alteration or suturing of gun shot wound creates problems. The evaluation of the wound whether it was entrance or exit wound ------ become evaluation of the wound whether it was entrance or exit wound ------ become difficult.difficult.

Four former United States presidents were assaulted by gun shot.Four former United States presidents were assaulted by gun shot.

1. Abraham Lincoln1. Abraham Lincoln

2. John F. Kennedy 2. John F. Kennedy

3. McKinley 3. McKinley

4. Garfield. 4. Garfield.

KENNEDY PHENOMENON: KENNEDY PHENOMENON:

Abraham Lincoln John F. Kennedy

McKinley

Garfield.