Laser Detection of Latent Fingerprints—Treatment with Fluorescers

Abstract

Abstract In 1976 a method for the detection of latent fingerprints by their inherent luminescence using continuous-wave (CW) argon-ion laser excitation [1] was discovered at Xerox Research Centre of Canada, where the first detection by this method of an identified print from an actual criminal exhibit (a fingerprint on the sticky side of a piece of black electrical tape) was also achieved. Basically, the laser procedure involves illumination of the exhibit under scrutiny with the blue-green light from the argon-ion laser and photography of the resulting yellow-green fingerprint luminescence. The viewing and photography are carried out in a darkened room. A filter is used to block the laser light scattered from the exhibit to prevent eye damage and film exposure by the laser light. Spectroscopic and chromatographic features of fingerprint material indicate that riboflavin is one of several inherent luminescers in fingerprint residue and our findings suggest potential for fingerprint age determination [2].