Volume 30, Issue 2 (April 1985)
Laser Detection of Latent Fingerprints: Difficult Surfaces
Fingerprint development techniques that use blue-green laser light suffer from high background fluorescence on substrates such as cardboard, wood, leather, and some metals and plastics. These substrates tend to exhibit little or no fluorescence under ultraviolet light, prompting us to search for procedures that yield visible fluorescence under this illumination. Specifically, chemical development with dansyl chloride and vapor staining with 9-methylanthracene were found to be useful when dealing with these substrates. Fluorescence excitation was possible either with an ultraviolet lamp or an argon-ion laser operating in the ultraviolet. Coumarin 535 vapor staining following 9-methylanthracene staining was also found effective.