1. Gunshot residue patterns on skin in angled contact and near contact gunshot wounds PRESENTER: Sommai Sangkaew 51312327

2. To identify how the weapon was use. To identify the criminal. 1 23 The Importance of Gunshot Residues in Forensic

3. Ammunition Target Muzzle- target-angles Gunshot residues Powder soot zone KEYWORD > > > > >

4. Ammu nition Keyword

5. The Content of a Bullet. Nitrocellulose (NC-powder) Keyword

6. A weapon that is used to shoot a bullet Two type of gun: –Revolver gun –Automatic gun 1 2 1: Revolver 2: Automatic Keyword Type of gun

7. Keyword Targ et an object, usually marked with concentric circles, to be aimed at in shooting practice or contests.

8. The angle in which the bullet hit the target Muzzle-Target angle (0˚) Muzzle- Target angle(45˚) Muzzle-Target angle

9. Small particles from the barrel of a gun when it is fired Consists of: –Antimony(Sb) –Barium(Ba) –Lead(Pb) Primer Gunshot Residue Particle identified by Scanning Electron Microscopy Gunshot Residues

10. Outer powder soot zone Inner powder soot zone Keyword Powder soot zone

11. To study the pattern and density of inner and outer powder soot zones which occur because of : Type of ammunition The barrel length Muzzle-target angle The distance from muzzle to target. PURP OSE

12. MATERIAL > > > > > Gun Cartridg es Target

13. 1).38 Smith and Wesson revolver 2) 9 mm SIG Pistol P210 automatic 3).22 L.R SIG Pistol P210 automatic MATERIAL >> Gun 1 2 3

14. .22 L.R 9mm Luger.38 Spl MATERIAL >> Gun

15. They used naturally tanned calf skin leather fixed on soap and gelatine block. MATERIAL >> Target

16. Type of gun Muzzle- target angle Lengths of barrels ammu nition.38 magnum 20, 30, 45,60-.38 Spl 9 mm SIG Pistol 20, 30, 45,60-9 mm 22 L.R SIG Pistol 20, 30, 45,60150, 250, 650 22 L.R The distance from muzzle to target is 0,5,10,15 and 20 mm METHO DS

17. The Inner powder soot zone can be more clearly defined and demarcated than outer powder soot zone RESUL TS

18. The Inner powder soot zones point to the direction of the muzzle. RESUL TS

19. When the Muzzle-target angle is increased, the Inner powder soot zone will be wider but the density of gunshot residues will decrease RESUL TS

20. When the length of the barrel increases, the Inner powder soot zone will be denser and smaller. RESUL TS

21. When the length of the barrel increases, the entrance hole will be on the rim of the inner powder soot zones. RESUL TS

22. The different types of the ammunitions will result in different densities of gunshot residues. RESUL TS

23. Gunshot residues on the target surface can be differentiate d in a inner and outer powder soot zone DISCUS SION

24. The outer powder soot zone is much less visible than the inner powder soot zone and may lack on human skin. DISCUS SION

25. With increasing muzzle target distance both inner and outer powder soot halo increase in size and decrease in density. DISCUS SION

26. In angled shots the inner powder soot halo shows an eccentric, elliptic shape which points towards the muzzle, regardless of ammunition, calibre and barrel length. DISCUS SION

27. The outer powder soot points away from the muzzle in angled contact and close contact shots DISCUS SION

28. SPECIAL THANKS T. Plattner, B. Kneubuehi, M. Thali, U. Zollinger, “ Gunshot residue patterns on skin in angled contact and near contact gunshot wounds” Associate Professor. Suda Riengrojpitak, Major adviser Police Lieutenant Colonel. Suphareark Arepornrat, Miner adviser Assistant Professor. Suksiri Vichasri Grams Every attendee of the seminar.