Firearm

Question 1

Def of weapon

Answer 1

An instrument discharging missile due to force of gases produced by burning of propellant in closed space

Question 2

Parts of a weapon

Answer 2

1- hand grib
2- barrel
3- action ( بيت النار)
4- muzzle

Question 3

Types of weapon

Answer 3

1- rifled
Short( 25 cm ) : -non automatic: revolver
-Semi automatic : pistol

Long (100 cm) : in military/ hunting
-non automatic: single bullet on pulling the trigger
-Automatic : group of bullets within seconds on pulling the trigger

2- non rifled
-Ghaffir
- military
- country gunshot ( homemade)
- sporting gun : double or single barrel

Question 4

Parts of rifled weapon

Answer 4

• grooves ( depression)
• ridges ( land)
  Alternating in spiral pattern

Question 5

Why making rifled weapon

Answer 5

It allows rational spin that increases
- velocity
- range of firing
-power of penetration
- stability by overcoming resistance of air , gravity

Question 6

What is rifling marks

Answer 6

Scratchs to the bullet that helps in identification of the weapon used

Question 7

Cartidge ?

Answer 7

Rifled

1- missile ( projectile )
2- propellant ( gun powder)
3- base
4- percussion cap
5- case ( cylinder)

Non rifled
1- external wad
2- internal wad
3- shots
2- propellant ( gun powder)
3- base
4- percussion cap
5- case ( cylinder)

Missile = bullet in rifled
= wads and shots in non rifled

Question 8

Sequence of events after firing

Answer 8

1- light : muzzle flash first then sound of the firing
2-explosive gases of missile causing tears , pinkish discolouration at the inlet ( 15 cm far)
3- flames causing burning of skin , hair
4- smoke causing blackening ( soot ) sround the inlet
5- unburnt powder particles causing ttatowing around the inlet

Question 9

Estimation of firing distance

Answer 9

1- powder marks
- THey include burning , blackening, tattoing around the inlet
- burning : of cloths , skin , hair ( comma shaped , singed )
- blackening : soot around the inlet ( can be wiped out )
- tattoing : redish brwon punctered lesions around inlet ( can’t be wiped out )

• burning = half of barrel
• blackening = 1 for short
  = 1 for long ( smokeless)
  = 1,5 for long ( black powder)
• tattooing = 2 for short
  = 2 for long ( smokeless)
  = 3 for long ( black powder)

MLI
1- diagnosis for firarm injuries
2- diagnosis for type of powder
3- differentiation between inlet , exit
4- estimation for distance
5- determination of direction

Question 10

Estimation of distance 2

Answer 10

• projectile

• shots
  The shots According to distance

1m ~> central hole 2 cm in dm
2m ~> smaller central hole with small dispersion of 4 cm in dm
3m ~> smaller central hole with dispersion of 9 cm in dm
4m ~> no holes , full dispersion of 16 cm in dm
10m ~> dispersion area of 60 cm in dm
20 m ~> full body is covered with shots
50 m ~> lose their penetration power & falls down

• wads
  External wads
  *Skin penetration at 1 m
• circukar abrasion within 1:3 m

Internal wads
* skin penetration at 3 m
* curcular abrasion within 3:10 m

• MLI
- diagnosis of firearm injuries
- differentiation between inlet & exit
- identification of weapon used
- estimation of distance
- identification of weapon bore

• bullets
• causes single hole
• distance is indicated from degree of penetration

Question 11

Def of firearm injury

Answer 11

• produced by missile
• may be accidental, suicidal, homocidal
• shows characters depending on
• type of weapon
• firing distance
• firing direction

Question 12

General characters of firearm injury

Answer 12

1- presence of inlet , exit
2- loss of substance especially at entrance due to + velocity , spinning movement , heat effects
3- presence of powder marks

Question 13

The inlets according to distance

Answer 13

• in contact :
Shape : lacerated or star or crociuate due gas expansion
Charc. : pink colour ( COHB)
Muzzle print
Powder marks (3)
Abrasion collar
Bullet wipe ( no ring )

• close
: 25 cm in short , 1,5 m in long
Shape : round or oval
Charc. : powder marks ( blackening , tattooing)
Abrasion collar
Bullet wipe ( soiling ring)

• intermediate
: 50 cm in short , 3 m in long
Shape : round or oval
Charc. : powder marks ( tattooing is pathognomonic )
Abrasion collar
Bullet wipe ( soiling ring )

• distant
: out tattooing range
Shape : round or oval
Charc. : abarasion collar
Bullet wipe ( soling ring )

Question 14

Compare between inlet , exit

Answer 14

Inlet
•Presence : usually except if it passes through body orifice ( mouth , ear)

• size : small except
* contact firing
* shots ( before dispersion)
* oblique
* contact firing& ricochet bullet

• loss of substance: more
• edge : more regular except in
- contact firing
- corregated area
Inverted except
- contact firing
- fattay area
- putrefaction

• powder marks : present except in
- distant firing
- ricochet bullet
- cloths ( intervening)

• abrasion collar : present
• bullet wipe : present

Exit

•Presence: usually except if
- retained in body
- passes through body orifice
- scattered through tissues

• size : large
• loss sustance : less

• edges : less regular
Everted except if there is supported exit

• powder marks : absent
• abrasion collar : absent
• bullet wipe : absent

Question 15

Whan can be 1 inlet with multiple exits ?

Answer 15

1- near shots ( non rifled ) firing
2- if the missile shatter bone and bony fragments passes out acting as extra missiles

Question 16

Determination of the direction

Answer 16

1- peripendiculaf firing :
- circular inlet surrounded by powder marks in a circular fashion

2- oblique firing :
- oval inlet and the powder marks are condensed in eccentric fashion

3- tangential firing :
- tract with powder marks being condensed at the beginning of tract

4- usually the inlet is opposite to exit thus drawing an imaginary line points to the position of assailant , however, bullet may alter due striking bone and cant be opposite to the exit and bullet track may not be linear

Question 17

injury related to special types of missile

Answer 17

1- plastic and rubber projectile
• are designed to weakens not to kill
• are used by police , security force for riot control
• they can cause lacerations, fractures sometimes penetration to soft tissues rg : eye globe

2- country made gunshot
- it cause tissue destruction and irregular shape as the cartidge ate filled with homemade shots made of lead , nails , stones , metal scraps

3- blank shells
- the cartidge are filled with small amout of powder enough to produce flash and sound of a real load with no projectile in it
- it is not that dangerous unless its close due the gush of gases damage

Question 18

Talk about fabricated firearm

Answer 18

Def : superficial injury with missile inside it and the margins are blackened

• there is no loss of substances
• no matching between powder marks and the distance told
• the cloths are spared

Question 19

What is doctors duty in firearm injury

Answer 19

(7)
1- emergency treatment with life saving measures
2- antibiotics regulary as contamination is suspected in gunshot injuries
3- report the police
4- documentation:
- photography with measuring scale
- sketches
- primary wound report is mandatory

5- radiologic imaging
X ray : to see retained missiles, fractures, bullet track
CT : is superior as it shows multiple views with higher resolution

6- any missile or forgien bodies as wads must be preserved first further investigation
6- clothes are preserved and examined for any defects or gunshot residues

Question 20

What is gunshot residues , where can it be

Answer 20

1- burnt and unburnt gun powder
2-
* hands of assailant
* cloths of him
* cloths of victim
* around inlet
* any target material in the scene
* swab in barrel of fired weapob
* in fired cartidges

Question 21

Def of
- abrasion collar
- bullet wipe

Answer 21

1- marginal abrasions as the missile abrades the skin on penetration
2- lubricant and greases on bullet surface wiped off on the wound edges