Firework displays as sources of particles similar to gunshot residue

Abstract

In light of past research being targeted to find specific particles which may be similar to gunshot residue (GSR), this project was formulated to detect any possible particulate by random particle fallout onto substrates at firework displays and to assess the impact this may have on GSR evidence. Firework residue was collected at a display site, from amongst spectators as well as from the author's hair 90min after the display. SEM-EDX analysis has detected such particulate in all three scenarios, with the firework particle population at large providing a solid ground for discrimination from GSR. Wind dispersal was found to decrease the particle population and subsequently, the latter's discriminatory power. Some particles, if treated individually were found to be indistinguishable from GSR. Findings also include residues which may mimic strontium based GSR as well as GSR which may be mixed with that from previous firings. The continuous changes made to primer and propellant compositions by manufacturers also call for greater consideration when classifying particles as originating from pyrotechnic devices. Furthermore, authorities such as police forces should be made more aware about the incidence of such particle transfer in firework related periods.