Detection of Pretreated Fingerprint Fluorescence Using an LED-based Excitation System

• NCJ Number: 223870
• Journal: Journal of Forensic Sciences Volume: 53 Issue: 4 Dated: July 2008 Pages: 823-827
• Author(s): Masahisa Takatsu Ph.D.; Osamu Shimoda B.S.; Kyoko Onishi B.S.; Akira Onishi Ph.D.; Naoki Oguri Ph.D.
• Date Published: July 2008
• Length: 5 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This paper describes the optimization of a light-emitting diode (LED)-based excitation system for the detection of pretreated fingerprint fluorescence.

Abstract

The novel prototype LED-based excitation system achieved good contrast when imaging both cyanoacrylate ester/rhodamin 6G treated fingerprints and ninhydrin/indium chloride treated fingerprints. The merits of the LED-based system compared with conventional light sources are low cost, simplicity, and easy maintenance. Compared to conventional light sources, the emission intensity of individual LED units is still weaker, making it insufficient for detecting weak fluorescent ridges. In order to address this issue, blue and green LED arrays composed of 90 LED units were used. Suitable low pass filters were designed for them. Thus, the experimental system tested consisted of blue and green LED arrays with the suitable low pass filters for illumination, high pass filters for viewing, a digital camera, and a computer. The description of materials and methods addresses optical design signal processing, and specimen preparation. 5 figures and 12 references