H. Brown et al., Image analysis of gunshot residue on entry wounds - II - A statistical estimation of firing range, FOREN SCI I, 100(3), 1999, pp. 179-186
A statistical investigation of the relationship between firing range and th
e amount and distribution of gunshot residue (GSR), used automated image an
alysis (IA) to quantify GSR deposit resulting from firings into pig skin, f
rom distances ranging between contact and 45 cm. Overall, for a Ruger .22 s
emi-automatic rifle using CCI solid point, high velocity ammunition, the to
tal area of GSR deposit on the skin sections decreased in a non-linear fash
ion with firing range. More specifically there were significant differences
in the amount of GSR deposited from shots fired at contact compared with s
hots fired from distances between 2.5 and 45 cm; and between shots fired fr
om a distance of 20 cm or less, with shots fired at a distance of 30 cm or
more. In addition, GSR particles were heavily concentrated in the wound tra
ct only for contact and close range shots at 2.5 cm, while the particle dis
tribution was more uniform between the wound tract and the skin surfaces fo
r shots fired from distances greater than 2.5 cm. Consequently, for future
scientific investigations of gunshot fatalities, once standards have been e
stablished for the weapon and ammunition type in question, image analysis q
uantification of GSR deposited in and around the gunshot wound may be capab
le of providing a reliable, statistical basis for estimating firing range.
(C) 1999 Elsevier Science Ireland Ltd. All rights reserved.