Evaluation of Electrochemical Corrosion, Electrodeposition, and Other Electroanalytical Methods as Investigative Forensic Techniques for Advancing Metal Substrate Analysis

Friction ridge skin, bearing unique patterns of epidermal ridges commonly known as fingerprints, has served as a crucial tool for identification since ancient times, with its utilization dating back to Chinese culture around 221 B.C. Today, friction ridge skin impressions remain vital evidence in forensic investigations, aiding in the identification of suspects. While fingerprints, palm prints, and footprints can all serve as identifying markers, this dissertation focuses specifically on fingerprints, broadly classified as visible or latent. Latent fingerprints, though invisible to the naked eye, constitute the majority of prints collected from crime scenes, necessitating physical, chemical, or physicochemical processing for visualization.Despite significant advancements in fingerprint development techniques, current methods often falter when applied to challenging substrates such as fired shell casings or submerged weapons. Electroanalytical methods, an underexplored avenue in latent fingerprint development, present a promising opportunity for innovative forensic investigation techniques. This dissertation surveys novel electroanalytical approaches aimed at enhancing the reliability and efficacy of latent fingerprint development. The research begins by elucidating optimal electrolyte solutions through soak tests and open circuit potential (OCP) experiments. OCP measurements further provide corrosion potential values for various metal alloys, contributing to a comprehensive understanding of fingerprint resolution enhancement while preserving fingerprint integrity. Subsequent investigations employ potentiodynamic, potentiostatic, and galvanostatic corrosion methods to exploit the corrosion caused by components of eccrine secretions for targeted fingerprint enhancement. Experimental results are systematically analyzed and compared to determine the efficacy of each method in enhancing fingerprint resolution while preserving the integrity of the fingerprint itself. Additionally, inductively coupled plasma-optical emission spectroscopy (ICP-OES) is employed alongside linear sweep voltammetry (LSV) measurements to provide real-time corrosion analysis, enhancing the understanding of targeted corrosion enhancement. Further exploration includes the investigation of electrodeposition and electroless deposition techniques for latent fingerprint enhancement, comparing their efficacy and preservation capabilities. Finally, a section in Chapter 6 discusses the potential reasons for the challenges in adopting these novel methods within forensic laboratories, such as budget constraints, staffing limitations, and rigorous quality assurance and legal admissibility standards. This dissertation offers insights into novel electroanalytical methods for latent fingerprint development, addressing critical challenges faced by current forensic techniques. The findings hold significant implications for forensic science, paving the way for more efficient and accurate identification processes in forensic laboratories.