TY - JOUR
T1 - A study into the distribution of gunshot residue particles in the random population
AU - Lucas, Nicholas
AU - Brown, Hayley
AU - Cook, Michael
AU - Redman, Kahlee
AU - Condon, Tanith
AU - Wrobel, Harald
AU - Kirkbride, Kenneth
AU - Kobus, Hilton
PY - 2016/5/1
Y1 - 2016/5/1
N2 - When considering the impact and value of gunshot residues (GSR) as forensic trace evidence, the likelihood of a suspect producing a positive GSR analysis result without having direct exposure to a firearm is a major consideration. Therefore, the random prevalence of GSR and 'GSR-like' residues in the wider population is a highly pertinent question when considering the probative value of such evidence. The random prevalence of GSR in two Australian jurisdictions - Victoria and South Australia - was assessed through the collection and analysis of GSR samples obtained from randomly selected members of the public. Volunteers were asked to declare any firearms use, hobbies or potential firearms exposure before allowing their hands to be sampled using aluminium GSR sample stubs coated in adhesive tape. A total of 289 samples, 120 from Victoria and 169 from South Australia were collected and analysed using scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). Across all samples, three 'characteristic' three-component Pb/Ba/Sb particles were detected from a single subject in South Australia, corresponding to an overall prevalence of 0.3%. Two-component 'consistent' particles were more prevalent, with Pb/Sb particles being the most frequently occurring, in 8% of samples, and in South Australia only. A number of samples, approximately 7%, showed populations of single element particles of Pb, Ba and Sb, which has the potential to generate a false positive for GSR if using a bulk analysis technique such as NAA or AAS. The prevalence of GSR or 'GSR like' particles in this study matches closely with similar surveys conducted in other jurisdictions. Such surveys are a useful foundation for the creation of a probabilistic method for the assessment of GSR evidence.
AB - When considering the impact and value of gunshot residues (GSR) as forensic trace evidence, the likelihood of a suspect producing a positive GSR analysis result without having direct exposure to a firearm is a major consideration. Therefore, the random prevalence of GSR and 'GSR-like' residues in the wider population is a highly pertinent question when considering the probative value of such evidence. The random prevalence of GSR in two Australian jurisdictions - Victoria and South Australia - was assessed through the collection and analysis of GSR samples obtained from randomly selected members of the public. Volunteers were asked to declare any firearms use, hobbies or potential firearms exposure before allowing their hands to be sampled using aluminium GSR sample stubs coated in adhesive tape. A total of 289 samples, 120 from Victoria and 169 from South Australia were collected and analysed using scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). Across all samples, three 'characteristic' three-component Pb/Ba/Sb particles were detected from a single subject in South Australia, corresponding to an overall prevalence of 0.3%. Two-component 'consistent' particles were more prevalent, with Pb/Sb particles being the most frequently occurring, in 8% of samples, and in South Australia only. A number of samples, approximately 7%, showed populations of single element particles of Pb, Ba and Sb, which has the potential to generate a false positive for GSR if using a bulk analysis technique such as NAA or AAS. The prevalence of GSR or 'GSR like' particles in this study matches closely with similar surveys conducted in other jurisdictions. Such surveys are a useful foundation for the creation of a probabilistic method for the assessment of GSR evidence.
KW - Energy dispersive X-ray microanalysis
KW - Forensic science
KW - Gunshot residue
KW - Primer residues
KW - Scanning electron microscopy
UR - http://www.scopus.com/inward/record.url?scp=84960863245&partnerID=8YFLogxK
U2 - 10.1016/j.forsciint.2016.02.050
DO - 10.1016/j.forsciint.2016.02.050
M3 - Article
VL - 262
SP - 150
EP - 155
JO - Forensic Science International
JF - Forensic Science International
SN - 0379-0738
ER -