Gun shot injuries PRESENTATION

gun shot

1. Gun shot injuries Firearm injuries

2. Definitions: A firearm weapon is a mechanical device that ejects projectile (s) at a high velocity. Firearm injuries are penetrating wounds where the causative instruments are missiles fired from firearms. In order to understand firearm injuries, a simple idea about firearm weapons is essential.

3. Types of firearm weapons : refile and non- refie Rifled weapons: (spiral guns) The rifled weapon has alternating ridges and grooves running spirally on the inner surface of the barrel ( فوهه البندقيه ) either clockwise or anticlockwise The idea of rifling: gives the bullet a spinning movement to overcome gravity and resistance of air, thus the distance of firing and power of penetration increase.

4. Refile and non-refile pores

5. Types of rifled weapons: According to barrel length: a. Long rifled, e.g. service rifle b. Short rifled, e.g. semiautomatic pistol and revolver According to automaticity: Non-automatic, e.g. revolver Semiautomatic, e.g. semiautomatic pistol Automatic, e.g. machine gun ( بندقيه الاليه ) The cartridge ( عيار ناري ) of the rifled weapon: It consists of a cartridge case , percussion cap , gun powder and a bullet

6. Non-rifled (smoothbore) weapons: non-rifled weapons have smooth barrel ( فوهه ). all are long, non-automatic weapons examples Sporting gun: (fire shots, fire slugs) The cartridge of the non-rifled weapon : consists of a cartridge case, percussion cap, gun powder, internal wad, the missiles (shots/ slugs), and external wad

7. Percussion cap (primer) Definition: It is a small disc present in the center of the base of all cartridges. It contains Powdered that spark by friction. Medicolegal importance: Helps to identify the weapon used in the crime, the empty case at the scene of the crime is compared with (size, site, shape, and depth of the wound). Which one is fired?

8. Propellant (gun powder): Two types, black and smokeless Black powder: composed of •Carbon 15% •Sulfur 10% •Potassium nitrite 75%, used in non-refile, make an alkaline reaction, at the site of wound making blackening and tattooing Smokeless powder: composed of Nitrocellulose •Nitroglycerine •Gelatin making neutral reaction at the site of the wound, making more burns and less blacking and tattooing

9. Results of the burning of powder on the body Gases: causing laceration of the inlet Flame: causes burning Smoke: causes blackening Unburnt particles: cause tattooing

10. Medicolegal importance of gun powder Diagnosis of firearm injuries. Is the wound from fire or from others cause?? Differentiate between the inlet and the exit. Estimation of the distance of firing: In short weapons: Flame (burning) and smoke (blackening) will not be found more than 15 cm ., Unburnt powder particles (tattooing) found up to 30- 45 cm. In long weapons: these distances are doubled of the above mentioned . In contact firing: powder can be found in the attacker and condensed in the lower part of the entry.

11. 4. Help in the detection of the type of weapon . 5. Determination of the direction of firing: oblique has a big inlet Missiles (projectiles): المقذوف Types: In non-rifled weapons: shots In rifled weapons: bullets

12. Wads: الحشوه produce either bruises or abrasions near the inlet or may penetrate the skin causing a second lacerated wound. These effects are present up to 5 meters. Medicolegal importance of wads Diagnosis of firearm injuries Diagnosis of the type of the weapon Estimation of the weapon’s bore Estimation of the distance of the firing Differentiate between inlet and exit

13. Shots: These are the missiles of non rifled weapons. They are made of lead. They are of two types: 1. Spherical ( ball )shots 2. Semi-cubical ( slugs ) Medicolegal importance of shots Diagnosis of firearm injuries Diagnosis of the type of the weapon Estimation of the distance of the firing from the shape of the inlet: Distance less than 1 m : common inlet without dispersion ( تشتت ) Distance 1-5 m : common inlet with partial dispersion Distance > 5 m: full dispersion

14. Bullets: These are missiles of rifled weapons, made of lead. Bullets may have blunted tips in short weapons or pointed tip in long weapons Bore (caliber/gauge) of the weapon : In rifled weapons: it is equal to the inner diameter of the barrel. It's measured in millimeters or inches. In non-rifled weapons: it is equal to the number of balls, It ranges from 8 to 32.

15. Characters of firearm injuries 1) Loss of substance ( فقدان جزء من النسيج )It is the most important character. It is due to: Very high velocity Spinning movement of the missile Heat production 2) Presence of two wounds ( inlet and exit ) -Exit may be absent if: The missile is retained in the body The missile passed through the body orifice (nose, mouth… etc ). -Causes of a single inlet and multiple exits: The bullet may shatter bone and fragments may go out separately Dumdum bullet ( المتفتته ) Near firing of non-rifled weapons

16. سحب الانسجه من مكانها )

17. Large inlet: Very near firing in the bony area up to 15 cm Shotgun injuries (multiple) 3. Dumdum bullet 4. Oblique firing Everted inlet: 1. Very near firing in bony areas 2. After putrefaction due to effect of gases 3. Inlet in a fatty area 4. Dumdum bullet

18. The appearance of inlet in (contact) and near firing (<15 cm): 1. In bony areas: the inlet is big, everted, and cruciate-shaped 2. In soft tissue: it is circular, about the diameter of the muzzle and regular For differences between suicidal, homicidal, and accidental firearm injuries see the next table

19. suicidal accidental homicidal

20. homicidal Accidental suicidal

21. Estimation of the distance of Firing This depends on: 1. Presence of Powder marks in the inlet wound 2. The missile in the wound: a. External and internal wads (in nonrifled weapon) b. Shots in non-rifled weapons (from the degree of dispersion ) 3. Estimation of the position of the attacker through empty cartridge, footprints, eyewitness. 4. Appearance of inlet: according to the criteria demonstrated previously

22. What are the guidelines in dealing with gunshot 1- All clothing containing gun powder or shot holes should be preserved 2- The clothing should be carefully wrapped in clean paper and folded as little as possible. 3- Package each item separately. 4- Ensure not to clean or wipe the wound(s) before the attending doctor has inspected the injuries. 5- Do not clean the recovered bullets. 6- Any recovered missile from a body should be air-dried and wrapped in paper. Washing may destroy trace evidence. 7. Keep the missile in a clean labeled container (write the patient's name, date... etc ).

23. 8- Enumerate wounds carefully 9- Describe each wound in detail 10- Examine body orifices, hair-covered regions and the posterior aspect of the body carefully for additional gunshot wounds. 11. Take X-rays of the injured body part(s) especially if there is an exit wound. 12. Consider other relevant medico-legal perspectives, such as alcohol or drug intoxication .

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