| Summary: | Firearm-related crime is classified as violent crime and surely it has given an impact to
general public safety. Study of gunshot residue (GSR) becomes important in investigating
shooting incidents. Detection of GSR can estimate firing distances. This study focused on GSR distribution pattern deposited on four different types of fabrics, shot at three
distances by four different types of pistols. 9 mm pistols and 9 mm ammunition were used
in test firing. All shooting tests were performed at Ibu Pejabat Polis Daerah (IPD) Kota Bharu, Kelantan. Physical observation, microscopic examination and chemical enhancement methods were used in detection of GSR. Results showed that, as shooting
distance increased, GSR particles decreased and dispersed widely. There was not much
difference in diameter of bullet and soot if the shooting distance more than 1 m. For close
range shot, GSR distribution pattern was quite useful to characterise the pistol used but not
strong enough to identify pistol. As muzzle-to-target increased, type of pistol cannot be
determined because the result showed no observable difference in term of GSR pattern and
bullet hole diameter. Chemical enhancement involving the application of Modified Griess
Test (MGT) in detection of nitrite residues as a by-product of combustion of gunpowder
was performed. The presence of dark-purple colour indicated positive result of nitrite.
Careful examination showed the decrease in the intensity of the colour in which the colour
was too fade to observe as the shooting distance increased. Nitrite can still be detected up
to 3 m on some fabric used and certain type of pistols. It is believed that, different pistols
act differently during firing the cartridge and discharge the GSR. Mesh size of fabric is important in attachment persistency of residues. GSR distribution pattern from 9 mm semi-automatics pistols on fabrics could be established by visual and chemical enhancement method.
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