Visualization of Dactyloscopic Traces on Cartridge Cases Using Electrochemically Prepared Polymer Films

A simple fingerprint visualization method based on the electrochemical deposition of polytoluidine blue (PTB) and polyneutral red (PNR) from a neutral environment with the possibility of minimal damage to the genetic information could facilitate fingerprinting from cartridge cases in forensic practice. The parameters of both visualization methods (supporting electrolyte, applied potential, deposition time or potential range, and number of cycles) were optimized until the imprint was sufficiently visible. The morphology and structure of modified fingerprint surfaces and polyphenazine films were studied using scanning electron microscopy. It is assumed that the method will be applied in the future to fired cartridges, which are crucial in forensics.