Understanding the persistence of both organic and inorganic gunshot residues (OGSR and IGSR) is essential for the accurate interpretation of specimens collected hours after firearm discharges. This study investigates the persistence of OGSR and IGSR on the shooter’s hands, forearms, face and on work desk, 24 hours after a high number of discharges. GSR were collected using carbon stubs on three individuals with high GSR prevalence risk (frequent firearm users) and two individuals with infrequent exposure to firearms. Organic compounds were first extracted and then analysed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Subsequently, IGSR particles were detected on the same stub using scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDS). The results of this study highlighted that both types of GSR could still be detected 24 hours after 23 to 100 discharges, despite activities such as showering, changing clothes, sleeping and working. Higher numbers of discharges (i.e. 100) produced more GSR, while fewer discharges (i.e., 30-50) generally resulted in lower amounts of residue being detected. The experiment with heavy-metal free ammunition resulted in significant amounts of OGSR and no PbSbBa particles, showing the added value of OGSR analysis for such munition types. GSR could also be detected in the offices of the shooters on objects such as their desk, mouse or keyboard. The results of this study should be considered when persons of interest have discharged a firearm several times in the 24 hours before collection occurs.
Minzière et al. (2026) studied this question.