NCJ Number
186431
Journal
Journal of Forensic Sciences Volume: 45 Issue: 6 Dated: November 2000 Pages: 1303-1306
Date Published
November 2000
Length
4 pages
Annotation
This paper describes the use of the polyvinyl-alcohol collection method (PVAL) to obtain information about gunshot residues from the hands for the purpose of determining whether the subject has fired a gun.
Abstract
The discharge of a firearm deposits gunshot residues (GSR) on the hand holding the weapon. The shooter's hand can be identified by the density distribution of GSR on his/her hands. In addition, if the gunshot wound is self-inflicted, there are often biological traces caused by backspatter of blood and tissue found on the hand. In the current experiment, the only inconvenience of PVAL was that the procedure took approximately 60 minutes, because three layers of liquid PVAL had to be applied and dried; therefore, the collection method was only applied to corpses. The improved and accelerated PVAL 2.0 uses a sandwich technique. Cotton gauze for stabilization is moistened with a 10-percent PVAL solution. A solid film of PVAL (Solublon) is spread on the cotton mesh. The gauze is then modeled to the hand and dried with a hair dryer. After removing the cotton gauze, the traces are embedded in the water-soluble PVAL. The procedure does not take more than 15 minutes. The results show the qualities and advantages of PVAL: topographical distribution of GSR; highest gain of GSR; sampling of all other traces like blood; backspatter, etc.; and humidity does not reduce the gain. In addition, with the new PVAL 2.0, dislocation of GSR or contamination are excluded. PVAL 2.0 can also be applied on live suspects. 1 table, 9 figures, and 9 references