GUNSHOT WOUNDS FIREARM INJURIES

FIREARMS Smoothbore ie Shotguns ---fire mass of pellets Rifled weapons ie Handguns & Rifles--- fire bullets Airguns—pistols & rifles---fire projectiles

SHOTGUNS Calibre size = Bore or Guage Common Guages are Historically,the number of balls (of barrel diameter) to equal a pound of lead Exception is the.410,which means it has a barrel diameter of inches

SHOTGUNS Single-Barrelled Double-Barrelled—may be Side-by-Side or Over-and-Under Repeating----single-barrelled,Pump-Action or Semi-Automatic

SHOTGUNS BARREL LENGTH Commenest lengths 28 inches 30 inches 32 inches Legal Minimum is 24 inches Sawn-Off Shotguns ---- ILLEGAL

SHOTGUNS CHOKE----a constriction over last few inches of the barrel May be built in and permanent or the gun may come with a selection of screw-in chokes Choke functions to delay the spread of the pellet pattern

SHOTGUNS CHOKE True-Cylinder Improved choke ¼ choke ½ choke ¾ choke Full choke

SHOTGUNS AMMUNITION is the Cartridge The Cartridge contains the lead shot (ie the pellets) which come in a variety of sizes Number Convention Low number = fewer BIG pellets High number = more SMALL pellets 6 = common game load

SHOTGUNS What comes out of the gun when it is fired? PELLETS WADS GAS FLAME POWDER---burnt and unburnt

SHOTGUN WOUNDS CONTACT WOUNDS Head ---- EXPLOSIVE Injury Chest and Abdomen --- circular wounds with blackened and seared margins May get a muzzle imprint

SHOTGUN WOUNDS < 2 feet ----single wound, ¾ to 1 inch 3 feet----single wound,scalloped margins 4 feet----entrance wound + satellite holes 10 feet----ragged central hole with numerous pellet holes Beyond 10 feet----pattern of multiple pellet holes

SHOTGUN WOUNDS WADDING < 5-6 feet----goes in the entrance wound Beyond that range, may strike separately Felt wads Plastic wads -----Maltese Cross between 1 to 2 feet

HANDGUNS REVOLVERS SEMI-AUTOMATIC PISTOLS All fire bullets Various Calibres

HANDGUNS What does the weapon discharge? Flame--- 1 to 2 inches Gas Powder---burnt and unburnt Soot ( Carbon ) Vapourised Metal BULLET

HANDGUN WOUNDS CONTACT WOUNDS----firm,loose,near INTERMEDIATE Range DISTANT

HANDGUN WOUNDS CONTACT WOUNDS Blackened,Seared edges Possible Muzzle Imprint Loose—ring of soot Near ---broader band of blackened,seared skin

HANDGUN WOUNDS CONTACT WOUNDS to the HEAD May get a circular wound with blackened,seared margins May get a wound with a muzzle imprint May get a Stellate-shaped wound as gases enter and the thin scalp which is stretched over bone balloons out Possible back-spatter into weapon

HANDGUN WOUNDS INTERMEDIATE RANGE POWDER TATTOOING is the characteristic feature Powder grains strike the skin causing punctate abrasions Multiple punctate reddish-brown to orange- red abrasions Approximate range-----1/2 inch to 2-4 feet

HANDGUN WOUNDS DISTANT Round or Oval wounds with an Abrasion Ring (usually though not always)

HANDGUN WOUNDS EXIT WOUNDS Rule of ODDS and EVENS Usually Larger and more Irregular than entry wounds Often slit-like or stellate N.B.---Shored Exit Wounds---uncommon---have an abrasion ring due to exit site in contact with ground or wall,or rarely due to tight clothing

GUNSHOT WOUNDS Scientific Examination of Clothing Test-Firing of Gun and Ammunition

RIFLE WOUNDS POWERFUL FMJ – Bullets ---tend to pass through and remain Undeformed Semi-jacketed bullets used as Hunting rounds---jacket peals back and the lead core mushrooms and disintegrates into scores of lead fragments

RIFLE WOUNDS High-Velocity Rifle wounds Enormously powerful and destructive Shock-Wave Cavitation Transmission of Energy via Fluid-filled Structures eg Arteries and Veins to produce additional injury at sites remote from the main track

GUNSHOT WOUNDS ACCIDENT? SUICIDE? MURDER? Need to consider the wound,the wound site,range of discharge,the scene etc. Preservation of Evidence(including fingerprints) GSR (gunshot residue) swabs Clothing Test-Firing