Detection of Firearm Imprints on the Hands of Suspects: Effectiveness of PDT Reaction

• NCJ Number: 192044
• Journal: Journal of Forensic Sciences Volume: 46 Issue: 6 Dated: November 2001 Pages: 1442-1446
• Author(s): Amihud Leifer M.Sc.; Yaniv Avissar B.Sc.; Shmuel Berger M.B.A; Hagay Wax M.Sc.; Yoel Donchin M.D.; Joseph Almog Ph.D.
• Date Published: November 2001
• Length: 5 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This study compared pyridyldiphenyl triazine (PDT) and three of its analogues as practical reagents for visualizing unseen impressions left on the hands of a person who had held a firearm.

Abstract

In the first experiment, 15 volunteers (eight males and seven females) between the ages of 19 and 44, all employees of the Israel Police, participated in the study. Two handguns from a preliminary list of 10 were chosen for the experiment. Each volunteer held the handgun firmly for 30 seconds. The hands were then sprayed with PDT solution, and then after a few seconds also with water, which enhanced the marks by providing a more polar environment. The visible marks were then photographed. The same procedure was repeated with each of the analogues. The quality of the results was assessed according to intensity and resolution (clarity). The second experiment involved 147 volunteers (104 males and 43 females), all trainees in the Israel Police Physical Training School. A selection of guns was provided in an effort to estimate the correlation between specific guns and the quality of the PDT resultant mark. Each volunteer held one of the guns, randomly selected, in the right hand for 30 seconds. The volunteer then held the same handgun in the left hand, again for 30 seconds. The right hand was sprayed with PDT immediately after contact with the weapon, and the left had was sprayed 1 hour later. Results were photographed and analyzed. Identifiable impressions of the metallic parts of the weapons were developed on the hands of 103 volunteers (70 percent). Results with females were slightly higher than with males; however, the difference was possibly statistically insignificant, thus requiring further study. Ferroprint and Ferrotrace, commercial preparations that are based on the PDT reaction, have become a part of the professional equipment of every crime-scene technician in Israel. 1 table, 2 figures, and 10 references