The visualization of fingerprints on metal substrates is a problematic issue in contemporary criminology. Com-mon methods of visualization (powder methods) are fast and simple but not very effective for metallic substrates. If fingerprints are deposited on metallic media, the common-ly used methods are based on the reaction of the reagent with the fingerprint material, making the ridges of the pa-pillary lines visible and creating a positive image of the fingerprint. However, for these classical methods, the pro-gressive aging of the fingerprint poses a problem, resulting in the loss of identification information. This review is devoted to the use of a thin conducting polymer layers for better visualization of fingerprints on problematic metal surfaces, which are widespread in the criminology. The fingerprint on a metallic substrate behaves like a template: it masks those areas where papillary lines are present, thus inhibiting polymer deposition. The result is a negative image of the fingerprint which means that only areas where the surface of the substrate is not blocked by the fingerprint are visible. This simple method of the finger-print visualization, based on electrodeposited polymers is fast, inexpensive and reliable. It can represent a great help for criminal investigators.

Katedra kriminalistiky a forenzních disciplín Fakulta právních a správních studií VŠFS Praha Estonská 500 101 00 Praha

Ústav analytické chemie Vysoká škola chemicko technologická Praha Technická 5 166 28 Praha

Visualization off fingerprints using conducting polymer layers

Literatura