Latent Fingerprint Visualization by Phosphorescence

Abstract

In this report, the bases of a practical and simple method for effective visualizing of latent fingerprints by phosphorescence was investigated. After the cyanoacrylate treatment of latent fingerprint, phosphorescence reagents were used to enhance the visualization of the fingerprints. Only simple chemical treatments, physical, photographic methods and conventional light source were required. Sophisticated, electronic time imaging equipment or chopper system as used in previous reports were not required. Twenty one phosphorescence reagents were examined in this experiment, and three of them, 4-biphenylcarboxylic acid, p-aminobenzoic acid and p-aminoacetophenone were effective enough for the enhancement of latent fingerprints visualization and conventional use. The former two reagents were excited at 254 nm, but the last one was excited at 350nm. This latent fingerprints detection method utilizing phosphorescence was considered effective, especially, when the back ground printing has a strong fluorescence.