1. Gunshot and Explosion deaths
Wojciech Golema
Forensic Medicine Department,
Medical Uniwersity in Wrocław

2. Main questions What was the shot direction (from where)?
What was the bullet direction in the body?
What weapon it was, what caliber?
What was the shot range (distance)?
Is there any data to support suicide, murder, accident?

3. Firearm
Firearm is a device that fires a projectile from a muzzle by mean of expanding gases produced by combustion of propellant (gunpowder). Projectile is capable to hit a target from a distance.

4. Pneumatic weapon
It is a device that fires a projectile from a muzzle by mean of expanding gas (which was compressed earlier). Projectile is capable to hit a target from a distance and it’s energy while leaving the muzzle exeeds 17J. The expanding gas comes usually from prefabricated cartridge with compressed gas or it is compressed by the piston in the cylinder.

5. Flint and percussion weapons
Black powder is poured down the barrel. Followed by a paper or cloth and a lead bullet. All was rammed down the barrel with a ramrod. Ignition system – „lock”. Thus the weapon consisted of „the lock, stock and barrel”. Lock has a cock (hammer) with a flint, pan (place for loose gunpowder) and a steel cover over the pan.

6. Small arms
Handguns: single-shot pistols, derringers, revolvers, automatics Rifles Shotguns Submachine guns Machine guns

7. Ammunition
Round (cartridge) = bullet + casing In previous years bullets were round. Now they are pointy or with rounded tip. Propellant: gunpowder („black powder” charcoal+sulfur+potassium nitrate); smokeless gunpowder (nitrocellulose/+nitroglicerin) Pyrodex – „synthetic” black powder

8. Missile wounds Firearms Bows & crossbows Air weapons
Catapults, other shooting objects
Explosion: blast and missile fragments

9. Energy transfer: High velocity of a bullet equals high kinetic energy.
Energy is transfered to tissues.
Energy transfer depends on bullet shape (pointy bullets travel deeper, but transfer less energy).
The denser the tissue the more energy will be transferred.

10. Cavitation
High velocity weapons (high kinetic energy) create wide cavity, not only bullet track.
Pressure changes create temporal cavity in tissues. The process is so violent it can create multipoint fractures without actually hitting a bone.

11. Tissue vulnerability play the most important role (ex. Liver).

12. Types of shot wounds Closed shot (entrance wound and canal)
Shot through (entrance, canal and exit)
Contact wounds, near-contact wounds, intermediate-range wounds, distant wounds

13. Unusual wounds
Graze and tangential wounds (bullet hitting the skin at shallow angle, without entrance nor exit, just superficial).
Superficial perforating wound (entrance and exit very close)
Reentry wounds and shoring of an entrance wound.
Ricochet from intermediary targets…

14. Shot wounds Entrance wound Canal Exit wound (if present)
A – grease ring
B – abrasion collar
C – burning
D – soot or smoke soiling and powder tatooing

15. Entrance wound is usually smaller, more regular, resembles the bullet size. Has grease ring and abrasion collar. Exit wound is usually bigger, irregular, doesn’t resemble the bullet.

16. Untypical entrance wound

17. „Kroenlein wound”

18. Range estimation Contact (+ monoxide – Paltauf syndrome)
Near contact (few centimetres)
Intermediate range (30-40 cm)
Distant

19. Hard contact

20. Loose contact

21. Angled contact

22. Incomplete contact

23. Very close range
Perpendicular Angled

24. Close range – powder tatooing

25. Bone wounds
Wound broadens like a crater in the direction of a shot.

26. Further examination Clothing Material from entrance wound & canal
Bones
Soot from hands (gunpowder, GSR, trace metal).
Bullets, casings, weapon (bullet must be removed with blunt tweezers).

27. Number of lands and grooves
Diameter of lands and grooves
Width of lands and grooves
Depth of grooves
Direction of rifling twist
Degree of twist

28. Apart from bullet and barrel comparison:
Cartridge markings.
Base markings.
Cythology and DNA typing of tissues on bullets
Fingerprinting (very hard)…

29. GSR

30. Canal assessment
Angle of entrance and exit canal (with relation to all body axis)
Length
Level of entrance & exit wounds (measured from feet).

31. Pellet rounds
Shotgun ammunition (shot):
Birdshot
Buckshot
Slugs

33. Other
Air weapons
Veterinary killers (captive bolt devices) & stud guns (industrial tools)
Rubber and plastic bullets
Potatoe gun…

34. Explosion Blast effect
Impact from projectiles or surrounding objects impelled by the explosion.
Burns from hot gas
Secondary injuries from falling masonry, beams dislodged by the expolsion.

35. IED – improvised explosive device

37. It’s much cheaper to make a mine than to remove it
It’s much cheaper to make a mine than to remove it. Therefore many countries just leave their mines in the ground…

38. Autopsy in explosion cases
X-ray !!!!
Victim identification
Chemical findings
Air embolism (vascular)
Any objects should be removed with a blunt tweezers (especially bullets).

39. Tasers
Designed to be safe – direct current, low amperage.

41. Electrocution Almost only accidents Direct current – fairly safe.
Amperage (amount of current flow) is the most important factor.
In very high voltage skin resistance has no meaning (body burns).
Lightning – „arborescent” or fern-like injury of the skin (Lichtenberg figures).

42. Effect – it „stacks” unfortunately
1 mA – tingling
5 mA – tremors of muscles
15-17 mA – contracture which prevents letting go of the electrical source
50 mA – contracture of all muscles, respiratory paralysis
mA – ventricular fibrillation
Above 1 A – ventricular arrest

43. Electric marks