Stubs Versus Swabs? A Comparison of Gunshot Residue Collection Techniques
The collection efficiency of two widely used gunshot residue (GSR) collection techniques—carbon-coated adhesive stubs and alcohol swabs—has been compared by counting the number of characteristic GSR particles collected from the firing hand of a shooter after firing one round. Samples were analyzed with both scanning electron microscopy and energy dispersive X-rays by an experienced GSR analyst, and the number of particles on each sample containing Pb, Ba, and Sb counted. The adhesive stubs showed a greater collection efficiency as all 24 samples gave positive results for GSR particles whereas the swabs gave only positive results for half of the 24 samples. Results showed a statistically significant collection efficiency for the stub collection method and likely reasons for this are considered.
Document Type: Research Article
Affiliations: 1: School of Chemistry, University of Reading, PO Box 224, Whiteknights, Reading RG6 6AD, UK. 2: Key Forensic Services Limited, Unit 1, ATU-1, Sir William Lyons Road, Coventry, West Midlands CV4 7EZ, UK. 3: Scientific Support Department, Northamptonshire Police, Wootton Hall, Northampton NN4 OJQ, UK. Also at: Forensic Research Centre, University of Leicester, Leicester LE1 7EA, UK.
Publication date: 01 May 2010