NCJ Number
222093
Journal
Journal of Forensic Identification Volume: 58 Issue: 2 Dated: March/April 2008 Pages: 265-276
Date Published
March 2008
Length
12 pages
Annotation
This article discusses a method that allows the detection of the fine lead cloud deposit, originating from a firearm discharge, directly into the target.
Abstract
The distance from which a shot was fired at a target, commonly referred to as the muzzle-to-target distance, can often be estimated from the distribution pattern of gunshot residue around the bullet entrance site, the determination of which can either help corroborate or refute suspects’ or witnesses’ statements. Little has changed in the methodologies used by criminalistic laboratories over the past 60 years. The method presented in this article provides criminalists with a capability to directly visualize various types of lead deposits (fine lead cloud from muzzle discharge, cylinder gap discharges, bullet wipe, bullet marks) on dark fabric that in the past would have been exceedingly difficult to view because of a lack of contrast with the sodium rhodizonate reaction. This direct approach appears to provide pattern distribution information superior to the commonly used transfer technique for the detection of the fine lead cloud deposit because the preponderance of the pattern is visualized directly on the substrate compared to a fair portion in the transfer method. Additionally, fabrics that create problems for the transfer method, because of their hydrophobic characteristics, are less problematic for the direct HCI method described here. Furthermore, interference from dyes that are transferred during the transfer method is obviated. An upcoming companion paper will report the results of a detailed study of the advantages and disadvantages of the dried versus wet HCI technique. Tables, figures, references