NCJ Number
96480
Journal
International Criminal Police Review Issue: 375 Dated: (February 1984) Pages: 34-41
Date Published
1984
Length
8 pages
Annotation
Infrared absorption microspectrophotometry offers an interesting new technique for analyzing the organic residue from smokeless powder after firing.
Abstract
To test the technique, several series of shots were fired on a test range using various weapons and various types of ammunition at specified firing distances. Analysis considered the powder extracted intact from cartridge cases and powder residues collected both from the case after firing and from around the bullet hole in the target, as well as from the hands of the marksman. Powder traces were collected and examined with a stereoscopic microscope. They were then tested in an infrared microphotometer. The technique is particularly useful for examining the powder residue often found on a gunman's clothing. Direct examination with a stereoscopic microscope combines several advantages such as rapidity, a large examination field, in situ search for powder particles, and their identification by shape and color. The analysis gives constant, characteristic spectra, all of which are similar regardless of the brand of ammunition used. Moreover, since it is a nondestructive technique, the sample analyzed is still available later for additional tests. Figures and eight references are included.