Grunge Template

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Gunshot residue patterns on
skin in angled contact and near contact
gunshot wounds
PRESENTER Sommai Sangkaew
51312327
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The Importance of Gunshot Residues in Forensic

• To identify how the
• weapon was use.
• To identify the criminal.

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• Ammunition
• Target
• Muzzle-target-angles
• Gunshot residues
• Powder soot zone

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Type of gun

• A weapon that is used to shoot a bullet
• Two type of gun
• Revolver gun
• Automatic gun

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an object, usually marked with concentric
circles, to be aimed at in shooting practice or
contests.
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Muzzle-Target angle

• The angle in which the bullet hit the target

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Gunshot Residues

• 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
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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.

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• Gun
• Cartridges
• Target

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MATERIAL gtgt Gun
1) .38 Smith and Wesson revolver
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2) 9 mm SIG Pistol P210 automatic
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3).22 L.R SIG Pistol P210 automatic
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MATERIAL gtgt Gun
.22 L.R
9mm Luger
.38 Spl
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MATERIAL gtgt Target

• They used naturally tanned calf skin leather
  fixed on soap and gelatine block.

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METHODS
Type of gun Muzzle-target angle Lengths of barrels ammunition
.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, 45,60 150, 250, 650 22 L.R
The distance from muzzle to target is 0,5,10,15
and 20 mm
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The Inner powder soot zone can be more clearly
defined and demarcated than outer powder soot zone
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The Inner powder soot zones point to the
direction of the muzzle.
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When the Muzzle-target angle is increased, the
Inner powder soot zone will be wider but the
density of gunshot residues will decrease
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When the length of the barrel increases,
the Inner powder soot zone will be denser
and smaller.
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When the length of the barrel increases, the
entrance hole will be on the rim of the inner
powder soot zones.
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The different types of the ammunitions will
result in different densities of gunshot residues.
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• Gunshot residues on the target surface can be
  differentiated in a inner and outer powder soot
  zone

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

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

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• 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.

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• The outer powder soot points away from the muzzle
  in angled contact and close contact shots

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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.