Comparison of the Physical Characteristics and Gunshot Residue in Fabrics after Firing with SEM/EDX Technique

Abstract

The objectives of this study were to compare gunshot residue in fabrics after firing at different shooting distances by Scanning Electron Microscopy (SEM) technique and to compare the amount of gunshot residue in fabrics after firing at different shooting distances by Energy Dispersive X-ray Spectroscopy (EDX) technique. This study was an experimental research. The

380-inch Walther semi-automatic handgun was used to fire at six different distances: 5 m., 10 m., 15 m., 20 m. and 25 m. and the firing was repeated 5 times per distance. Descriptive statistic was used to analyze data which was reported as mean and S.D. of elemental contents. The results showed that at the firing distance of 25 m., the largest particle size was 4.17 microns and the smallest particle size was 1.10 microns at the close range. The three main elements were antimony (Sb), barium (Ba), and lead (Pb). At the firing distance of 5 m., there were the highest amount of barium and the low amount of gunshot residue at the close range. At the firing distance of 5 m., the highest percentage of gunshot residue elements was found as follows: (reported as mean ‡ standard deviation) antimony (Sb) of 7.37 ‡ 3.08, barium (Ba) of 110.25 ‡ 4.81 and lead (Pb) of 27.55 ‡ 8.59. At the firing distance of 20 m., the amount of gunshot residue decreased. This research can be applied in forensic science to benefit practitioners and verification officers because this technique did not destroy the witness material and took less time to analyze.