Narayan P. WAGHMARE¹, Anadamoy MANNA², Mottamari S. RAO³, Akhlesh Kumar DOHARE^1
1Central Forensic Science Laboratory, Kolkata, India
²Department of Physics, Jadavpure University, Kolkata, India
³Directorate of Forensic Science, New Delhi, India

The presence of antimony, lead, barium, nickel, copper and silicon or combinations of these elements at the scene of crime can confirm whether firing has taken place or not. In this paper, laboratory test firings were carried out at a target consisting in a paper and glass layers using .315"/8 mm calibre ammunition and an Indian sporting rifle. Blackened bullet residue particles obtained in this manner found on a paper target supported by various thicknesses of window panes were studied. A very large percentage of blackened bullet residue particles containing lead, antimony and silicon were found in these tests. Samples taken from the surface of the paper target were examined by means of a scanning electron microscope coupled with an energy dispersive X-ray analyser (SEM-EDX).
Observations relating to forensic problems, such as proximity between the shooter and the windowpane target, size of hole, direction of firing etc. are elaborately discussed in relation to the blackened bullet residue pattern. Bullet residue giving the appearance of blackening found on one of  two layers of a target could be confusing to the forensic ballistics expert at the crime scene  it could be wrongly interpreted as powder pattern. The current study was undertaken in order to avoid such mistakes in cases of using .315"/8 mm calibre ammunition and an Indian sporting rifle.

Firearm; Glass target; GSR; Blackened bullet residues; Blackening; SEM-EDX.