Development of Microscopical Methods for the Systematic Analysis of Chemically Reacted, Improvised Low Explosives and Related Residues

Commercially available and homemade black powders, black powder substitutes, fireworks/pyrotechnics, smokeless powders, flash powders, and other improvised explosive ingredients are common constituents in homemade and improvised chemical explosive devices. Although microscopy is often mentioned, there exists no common methodology or systematic approach available to the forensic scientist for the analysis of the resulting residues after such a low-order explosion or chemical reaction using these types of ingredients occurs. Because any energetic event is likely to produce debris with varying degrees of chemically reacted, charred, combusted, partially combusted, oxidized, reduced, and deflagrated ingredients, particles comprised of microscopic chemical substances remain as combustion product residue and ash. This research will use a microscopical approach to investigate the particles and residues resulting from the controlled burning and ashing of small quantities of chemically reacted samples of black powder, black powder substitute, fireworks/pyrotechnics, flash powder, and smokeless powders formulations. The samples will be obtained from existing reference collections and obtained through readily available commercial suppliers of ingredients frequently encountered in improvised low explosive devices. Stereomicroscopy (SM) and polarized light microscopy (PLM) together with microchemical tests will be used with the goal of developing methods or procedures that will also satisfy a basic scientific need: to sufficiently determine a chemical substance’s identity with near absolute certainty as the existing analytical techniques permit. The research will integrate a time-tested and proven microscopical approach used by McCrone Research Institute in Chicago to perform analyses, research, educate the forensic science community, and integrate its own systematic approach to particle analysis and identification like that presented in its many publications including, The Particle Atlas and The Microscope journal together with, for example, the Alcohol, Tobacco, and Firearms, and Explosives’ published methods, “Spot Tests: Systematic Analysis of Low Explosives” (revised, 1988), and others currently utilized by various U.S. forensic science crime laboratories.

Note: This project contains a research and/or development component, as defined in applicable law, and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14).

CA/NCF