LAUSR

Abstract Following a shooting or explosive event, such as the explosion of an improvised explosive device, smokeless powders (SP) and smokeless powder residues (SPR) may be recovered as evidence. The analysis of SPR may allow for an association to the SP, which can provide an evidentiary link. In this study, the correlation between SP and SPR is explored via Sorensen-Dice similarity coefficients and Pearson correlation coefficients. Additionally, the Sorensen-Dice similarity coefficients between SPR and expected pyrolysis products, obtained from the burning of SP compound standards, are explored to determine whether SPR composition may be predicted based on initial SP composition. Results indicated that the similarity between SP and SPR is highly composition dependent, with samples containing diphenylamine along with nitroglycerin or 2,4-dinitrotoluene exhibiting higher similarity scores, as well as those containing dibutyl phthalate. Comparison of SPR to expected pyrolysis products indicated that the ability to predict SPR composition is also dependent on the initial SP composition. The complexity of burning a mixture, such as SP, compared to burning single components may contribute to the generally low similarity coefficients observed in this comparison.