Study of unusual phenomenon of contact firing on gelatine block using .38 Special revolver--forensic importance.

Gunshot wounds in suicide cases are self-inflicted wounds. Self-inflicted wounds in suicide cases are usually caused by contact firing and are of great forensic significance. Evaluation of contact wound may be associated with difficulties if the bore gets obstruction prior to firing. This paper investigates the phenomenon and interprets the results of test firing conducted on 20% gelatine block at 10 degrees C, using .38 Special revolver with obstruction of a bullet in the bore. Test firings were conducted in three different muzzle-target contact conditions keeping the muzzle pressed against the gel block in each case. The physical evidence and the wound ballistic parameter namely bullet track, remaining velocity of the bullets and volume of permanent cavity have been studied. When compared with the results of contact firing conducted with the same firearm without having any bore obstruction under similar conditions, it has been found that the physical evidence and the wound ballistic parameters would be helpful for interpretation of such unusual incidents for forensic inference.