Visualization Methods of Latent Fingerprints on Metal Substrates/Cartridges

Abstract

Despite the development of DNA analysis methods, fingerprint comparisons are still the most common and credible way to identify people when clarifying crimes and other forensically relevant events. Visualization of fingerprints applied to a metal surface, which may be curved (most often cartridges), often represents a difficult task, so that new methods are constantly being developed to get a high-quality visibility of fingerprints. This work describes the most important methods of visualization of fingerprints applied on metal substrates and especially on cartridge cases. So far, there is no suitable technique for making fingerprints visible on fired cartridges. Gun blue techniques, combined techniques with cyanoacrylate and, more recently, electrochemical deposition of polymer films potentiostatically or by cyclic voltammetry, which are fast, cheap and usable in the field, represent a promi­sing way.