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GUNSHOT WOUNDS FIREARM INJURIES Slide 2 FIREARMS Smoothbore ie Shotguns ---fire mass of pellets Rifled weapons ie Handguns & Rifles--- fire bullets Airgunspistols & rifles---fire projectiles Slide 3 SHOTGUNS Calibre size = Bore or Guage Common Guages are 12 20 16.410 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 0.410 inches Slide 4 SHOTGUNS Single-Barrelled Double-Barrelledmay be Side-by-Side or Over-and-Under Repeating----single-barrelled,Pump-Action or Semi-Automatic Slide 5 SHOTGUNS BARREL LENGTH Commenest lengths 28 inches 30 inches 32 inches Legal Minimum is 24 inches Sawn-Off Shotguns ---- ILLEGAL Slide 6 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 Slide 7 SHOTGUNS CHOKE True-Cylinder Improved choke choke choke choke Full choke Slide 8 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 Slide 9 Slide 10 SHOTGUNS What comes out of the gun when it is fired? PELLETS WADS GAS FLAME POWDER---burnt and unburnt Slide 11 SHOTGUN WOUNDS CONTACT WOUNDS Head ---- EXPLOSIVE Injury Chest and Abdomen --- circular wounds with blackened and seared margins May get a muzzle imprint Slide 12 SHOTGUN WOUNDS < 2 feet ----single wound, 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 Slide 13 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 Slide 14 Slide 15 HANDGUNS REVOLVERS SEMI-AUTOMATIC PISTOLS All fire bullets Various Calibres Slide 16 Slide 17 Slide 18 Slide 19 Slide 20 HANDGUNS What does the weapon discharge? Flame--- 1 to 2 inches Gas Powder---burnt and unburnt Soot ( Carbon ) Vapourised Metal BULLET Slide 21 HANDGUN WOUNDS CONTACT WOUNDS----firm,loose,near INTERMEDIATE Range DISTANT Slide 22 Slide 23 HANDGUN WOUNDS CONTACT WOUNDS Blackened,Seared edges Possible Muzzle Imprint Loosering of soot Near ---broader band of blackened,seared skin Slide 24 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 Slide 25 Slide 26 Slide 27 Slide 28 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 Slide 29 Slide 30 HANDGUN WOUNDS DISTANT Round or Oval wounds with an Abrasion Ring (usually though not always) Slide 31 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 Slide 32 Slide 33 GUNSHOT WOUNDS Scientific Examination of Clothing Test-Firing of Gun and Ammunition Slide 34 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 Slide 35 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 Slide 36 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 Slide 37 Slide 38