การตรวจหาลายนิ้วมือแฝงบนปลอกกระสุนปืนหลังยิงด้วยน้ำยารมดำปืน

Abstract

The purpose of this research is to study the results of using gun-blueing to detect the latent fingerprints on fired cartridge cases, and to compare the effects of using gun-blueing in finding latent fingerprints on fired cartridge cases spanning different time periods. The blueing reagent is the commercial product brand SOLID GUN BLUE CREME. The gun-blueing mixed with water at a ratio of 10 gram / water 200 millilitre was used for all test sample firearms. The firearms used were semi-automatic guns 9 mm, loaded with the 9 mm Luger brass bullets. The detection of latent fingerprints on the fired cartridges process was measured by three methods: 1) laid the fingerprints on the ammunition after firing and detected by gun-blueing; 2), 3) kept the fired cartridges for 15 and 30 days after firings and detected with the gun-blueing consecutively. The research found that with the three methods, the latent fingerprints could be found any time and persisted for 30 days which were 97.77, 95.55, and 91.11 detectable percentage respectively. The analysis of variance found that there was no significant difference among the three steps (P ≤ 0.05).