Detection of gunshot residue by use of the scanning electron microscope

Particle analysis techniques provide much more information useful for identification of gunshot residue than the conventional analytical techniques that measure only the concentration of elements averaged over the entire specimen. By combining the morphological information by microscopy with elemental analysis by X-ray fluorescence, the SEM provides definitive identification of residue particles. Therefore, the particle analysis technique should be more revealing in situations where conventional methods fail as the quantity of residue approaches the background level.