NCJ Number
225603
Journal
Journal of Forensic Sciences Volume: 53 Issue: 6 Dated: November 2008 Pages: 1381-1386
Date Published
November 2008
Length
6 pages
Annotation
This article reports on the procedures and results of a protocol that used the techniques of atomic force microscopy (AFM) and Fourier transform infrared attenuated total reflectance (FTIR/ATR) spectroscopy in the analysis of gun-shot residue (GSR), in order to determine whether these procedures could determine shooting distance and the identification of gun powder manufacturers.
Abstract
The research found that the AFM images of GSR showed that the size distribution of the GSR particles was inversely proportional to the shooting distance. The images indicate that the average size of the deposited GSR particles becomes larger as the shooting distance is shortened. Since this may only apply to certain particles with certain morphology, further testing is required to determine a general principle for the role of shooting distance in the GSR particle size distributions. The identification of the specific compounds in the GSR by FTIR/ATR was not possible, however, because it was a mixture of the debris of several compounds that composed the residue. On the other hand, the GSR from different cartridges had characteristic FTIR/ATR bands that might be useful in differentiating the powder manufacturers. This suggests that the development of AFM and FTIR/ATR databases for various powder manufacturers may prove useful in the analysis and identification of GSR. The size, morphology, and density of GSR particles were characterized by AFM, using a Quesant Q-Scope 250 Nomad from Ambios Technology, Inc., in Santa Cruz, CA. The tapping mode was used because of its high resolution capabilities. One of the advantages of AFM is that it is easy to make quantitative measurements of particle sizes. The ATR measurements of GSR were made on a Tensor 27 FTIR spectrometer with a Hyperion 1000 ATR microscope accessory. 6 figures and 17 references