Recovery of Latent Fingermarks From Evidence Exposed to Ionizing Radiation

• NCJ Number: 226894
• Journal: Journal of Forensic Sciences Volume: 54 Issue: 3 Dated: May 2009 Pages: 583-590
• Author(s): Michael Colella M.Sc.; Andrew Parkinson B.Sc.; Tegan Evans B.Sc.; Chris Lennard Ph.D.; Claude Roux Ph.D.
• Date Published: May 2009
• Length: 8 pages
• Grant Number(s): NSST 06-031
• Sponsoring Agency: Australian Federal Police; Australian Nuclear Science & Technology Organisation (ANSTO); Australian Government
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This study examined the ability of common latent-fingerprint-detection reagents and techniques to recover latent-fingermark evidence from a variety of substrates that had been exposed to ionizing radiation.

Abstract

With the exception of glass and aluminum substrates, radiolysis had a significant effect on the quality of the developed fingermark, due partly to the damage to ridge characteristics that resulted from radiolytically induced interactions between the substrate and the organic fingermark compounds. In addition, the radiolytic degradation and subsequent alteration to the physiochemical attributes of the various substrates may have undermined the ability of the detection technique to target the latent fingermark components. The decreased mechanical properties caused by this radiolytic degradation also made complex multisite enhancement processes problematic. These difficulties were observed for the substrates of office paper and hard and soft plastic; however, for glass and aluminum substrates exposed to ionizing radiation, processing and visually enhancing latent fingermarks with common detection reagents and techniques was successful. The premise of the research was that the latent fingermarks would be located in close proximity (1, 10, and 100 mm) from an unshielded source of ionizing radiation for a measured time period that ranged from 24 hours to 7 days. The research used a number of radioactive sources, commonly available in Australia, that pose the greatest security risk. The absorbed dose values for the forensic samples were calculated under described parameters, ranging from 6.7 Gy to approximately 11 Mgy. Latent fingermarks from five predetermined “good” donors were deposited on a range of porous and nonporous substrates prior to exposure to the irradiation exposure. The reagents and techniques used in the processing of the latent prints after this exposure are described. 2 tables, 8 figures, and 26 references