Paper Title
Study on the Duration of Gunshot Residue after Shooting from 9 mm Pistolon Back of Hands and Palms

This study aimed 1) to compare the elemental composition of the gunshot residue on the hand after shooting atdifferent durations 2) to study the correlation between the elemental components of the gunshot residue and the durationafter 9 mm pistol shooting. The gunshot residues werecollected from back of the hand and the palm of both hand sides aftershooting at 6, 8 and 10 hours. Then, the elemental compositions of gunshot residue including antimony, barium and lead byInductively coupled plasma (ICP). Interestingly, The quantity of antimony on the back of right and left hands were variedfrom 10 ppb to less than 20 ppb. Therefore, it is unlikely to use the quantity of antimony to prove that suspects are involvedin 9 mm pistol shooting. The relation between the amount of gunshot residue and time after shooting determined byFriedman test revealed that the amount of gunshot residue has statistically reduced with time after shooting (p<0.05). Theresults of this study would be helpful for 9 mm pistol forensic investigation Index Terms - Gunshot Residue, Duration