Harnessing Electron Microscope for Trace Evidence Analysis

Abstract

Trace evidence analysis is essential in criminal investigations as it provides vital information for establishing connections between suspects and scenes. Minute or complicated trace evidence is sometimes difficult for traditional microscopic techniques to handle. At micro- and nanoscale, electron microscopy (EM) shows great promise as a potent technique for characterization and visualization. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) offer valuable insights into morphology, chemical composition, and crystalline structure of trace evidence, enabling the identification and differentiation of similar materials. TEM allows high-resolution examination of paint components, dirt particles, gunshot residues (GSR), fibers, hair structures, glass shards, nano-particles, explosive materials, etc. In forensic investigations, SEM is a crucial instrument, especially when it comes to GSR analysis, which uses SEM to correlate bullets to firearms more successfully than visual approaches. Additionally, SEM plays a major role in the examination of gemstones and jewelry by identifying manufactured and natural gems, analyzing surface imperfections, and determining elemental compositions. SEM also improves forensic inspection in non-conductive material analysis, paint and fiber analysis, filament bulb investigations, handwriting analysis, and counterfeit detection. The adoption of EM in forensic trace evidence analysis has potential to revolutionize the field, offering valuable insights that were previously unattainable.