Gunshot Wounds Flashcards

Question

Features of intermediate range wound

Answer 1

Few cm to 1m - arms reach Powder tattooing - unburnt or partially burnt propellant grains - individual reddish-brown punctate abrasions - vital reaction - rim of bruising - eccentric pattern if angled entry - spread depends on powder, range and barrel - reaches up to 30-40 cm

Answer 2

``` Beyond 1m - beyond arm's length No flame effect No soot effect No propellant tattooing Bullet is on its own Skin defect with marginal abrasion - circular if impact at right angle - elliptical if impacting at another angle ```

Answer 3

``` Entry - circular defect - diameter < bullet - abraded margin - soot - propellant Exit - irregular shape - diameter > bullet - no abrasion - near exit ```

Answer 4

Spheroidal particles of barium, lead and antimony compounds from primer - condensation and solidification of molten and vaporised primer and bullet materials Newer lead-free ammunition Deposited on radial side of firing hand Cotton tipped swab moistened with HCl or HNO3 Sent for forensic scientific analysis

Answer 5

Hammer within firearm strikes outside of priming cap crushing explosive Shock-sensitive chemical compound explodes igniting secondary charge of gunpowder Temperatures exceed 2000°C Unburnt powder and vaporised metallic components from priming cap remain within recently formed gasses Increase in pressure causes ejection of bullet from casing and barrel Spherical particles formed are composed of elements present in the primer therefore making gunshot residue unique

Answer 6

``` Flame - 15cm Smoke - 38cm Powder tattooing - 60cm Wad - 1m Satellite holes - 2m Uniform peppering - 10m ```

Answer 7

``` Smooth barrel Fired from shoulder Fires multiple pellets Types - single shot - double barrel - over and under - bolt - lever - pump - autoloading ```

Answer 8

Number of balls of lead exactly fitting the barrel diameter which make up 1lb in weight - .410 is 10.2mm internal diameter - 20 gauge is 15mm - 12 gauge is 18.2mm - 10 gauge is 21 mm

Answer 9

Taper towards muzzle keeping shots more closely clustered Measured as % shot striking within 30" target circle at range of 40 yd - cylinder = 30% - improved cylinder = 40% - modified choke = 50% - full choke = 60%

Answer 10

``` Crimped plastic tube Shot Wad - plastic Powder Primer Brass head plate ```

Answer 11

``` Plastic spring shaped wad 12g, 16g and 20g have 4 petals .410 has 3 petals Pushes shot out of barrel Contributes to wound - < 1f not yet opened - 1-3 ft abrasions from petals - > 3 ft folded back - 8-10ft strikes alongside entry Indicates manufacturer and gauge ```

Answer 12

``` Very mutilating - gas - energy of shot Scalp laceration Skull fracture Brain may be blown out Most pellets and wad may exit ```

Answer 13

``` Circular entry = muzzle diameter Muzzle imprint Soot smudging Burning or melting of clothes Cherry pink wound margin - CO ```

Answer 14

``` Small circular defect < 2' No tattooing > 3' Scalloped margins by 3' Satellite holes (fliers) by 4' Cuff of satellite holes by 6' Beyond 10' entry depends on - range - length and choke of barrel - ammunition Test firing required ```

Answer 15

``` Rare in females Contact wound -> presumption of suicide HV blood splatter on steadying hand GS residues on firing hand Evidence of test firing Sites of election - head = 80% - chest = 15% - abdomen = 5% ```

Answer 16

``` Beware of artefacts and loss of evident Take X-rays Examine clothing for burns, tattooing and gunshot residue Examine hands - soot - blood - residues Recover projectiles - bullet, pellets - propellant, wadding ```

Answer 17

``` Shored or partial exit wounds Bullet ricochet out of and within body Separation of bullet jacket and core Projectiles may embolise or move Plastic wad and AI jacket invisible on x-ray X-ray may magnify projectiles Snooker ball effect of pellets ```