The analysis of organic and inorganic gunshot residue from a single sample

Ellen Goudsmits; Lauren S Blakey; Kal Chana; George P Sharples; Jason W Birkett

doi:10.1016/j.forsciint.2019.03.049

The analysis of organic and inorganic gunshot residue from a single sample

Forensic Sci Int. 2019 Jun:299:168-173. doi: 10.1016/j.forsciint.2019.03.049. Epub 2019 Apr 8.

Authors

Ellen Goudsmits¹, Lauren S Blakey¹, Kal Chana², George P Sharples¹, Jason W Birkett³

Affiliations

¹ School of Pharmacy and Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
² CellMark Forensic Services, P.O. box 265, Abingdon, OX14 1YX, Oxfordshire, UK.
³ School of Pharmacy and Biomolecular Sciences, Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK. Electronic address: J.W.Birkett@ljmu.ac.uk.

PMID: 31055135
DOI: 10.1016/j.forsciint.2019.03.049

Abstract

The detection and interpretation of gunshot residue (GSR) can play an important role in the investigation of firearm related incidents. Recently, the potential of organic compounds to provide an additional means to discriminate between GSR and environmental particles, in particular in cases where lead-free ammunition is used, has been highlighted. This work describes a method for the extraction and detection of complementary organic and inorganic compounds from a single GSR sample, using a methodology that makes implementation in the current standard procedure feasible. GSR samples were collected from the shooter's hands following double and single discharges, using the traditional adhesive carbon aluminium stubs. Analysis of organic compounds was performed using solid-phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), followed by analysis of the traditional inorganic particles using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). Detection of both categorised organic GSR compounds (e.g. ethyl centralite, diphenylamine and 2-nitrodiphenylamine) and characteristic inorganic GSR has been achieved. Given the fact that the detected organic GSR compounds are relevant with respect to the confirmation of GSR materials, this method has successfully demonstrated the ability to obtain a total chemical profile from a single GSR sample, which has the potential to increase the probative value of GSR evidence.

Keywords: Ballistics; Forensic science; Gunshot residue; Scanning electron microscopy; Solid-phase microextraction.