AFTE Store - Applications of Chemical Tests and X-ray Fluorescence Spectroscopy at Bullet Impact Sites

Chemical testing of suspected bullet impact sites can be useful in detecting the presence of metal residues. The applications of four colorimetric tests (dithiooxamide (DTO) and 2-nitroso-1-naphthol (2-NN) tests for copper, dimethylglyoxime (DMG) for nickel, and sodium rhodizonate for lead) were explored for their use in the detection of metal residues left at bullet impact sites. Four types of ammunition (lead, brass jacketed, copper jacketed, and nickel-plated) were used to create impact marks on a variety of surfaces encountered at indoor and outdoor shooting scenes. Sections of the chemical lifts were analyzed using x-ray fluorescence (XRF) spectroscopy. In addition to confirming the presence of residues detected by the colorimetric tests, other elements were detected and identified using XRF spectroscopy.