NCJ Number
217219
Journal
Journal of Forensic Sciences Volume: 52 Issue: 1 Dated: January 2007 Pages: 75-78
Date Published
January 2007
Length
4 pages
Annotation
This paper proposes a novel method for the estimation of an intermediate-long firing distance (0.75 to 3 m), based on the characterization and chemical analysis of the smokeless gunshot powder particles on the target.
Abstract
The study found that in the firing distance range of approximately 0.75 to 3 m, when there were only a few particles on the target, alkaline hydrolysis followed only by the Modified Griess Test was not able to confirm that the particles were smokeless powder. This study found that using an adhesive lifter to transfer the suspected smokeless powder particles--followed by alkaline hydrolysis, the Modified Griess Test (MGT) visualization process, gas chromatography/mass spectrometry (GC/MS), and gas chromatography/thermal energy analysis (GC/TEA)--might confirm the chemical identification of gunpowder residues on samples as small as a single particle. GC/MS was more useful than GC/TEA for analyzing smokeless powder residues. Depending on the compounds identified, additional information may be collected on the type of ammunition used. This new method may also confirm the origin of the nitrite group as gunpowder and exclude the origin from substances such as paints or lacquers. By using this procedure and confirming that the suspected particles on the target are indeed gunshot residue, the intermediate-long firing distance can be estimated with very few residue particles and provide information for the classification of ammunition type. GC/TEA was used for the analysis of nitroglycerine (NG) and 2,4-dinitrotoluene (2,4-DNT). GC/MS was used for the identification of organic components such as DNT, NG, and some stabilizers. 1 table, 2 figures, and 15 references