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Evaluation of Existing Technologies for Novel Analysis and Probabilistic Interpretation of Organic Gunshot Residue

NCJ Number
Date Published
July 2017
5 pages
This "Technical Note" reports on the National Institute of Justice Forensic Technology Center of Excellence's (FTCoE's) commissioned evaluation of novel adaptations to two existing technologies for their suitability as screening methods for the presence of organic particles in gunshot residue (OGSR).
Firearms exposure has traditionally been monitored by screening for the presence of inorganic particles prevalent in gunshot residue from the primer in ammunition. Recent research efforts have explored alternative approaches for monitoring firearms exposure that screen for the presence of organic components of GSR that come from propellants and stabilizers. The FTCoE commissioned scientists at West Virginia University (WVU) to evaluate two existing technologies for such screening. The methods evaluated were ion mobility spectrometry (IMS) and inlet thermal desorption gas chromatography mass spectrometry (GC-MS). A thermal separation probe (TSP) was evaluated as an inlet to a GC-MS system for the analysis of OGSR components. The modified IMS approach developed by the WVU scientists reduced the false-positive rate to zero for OGSR. The modified GC-MS system used by the WVU scientists was disappointing in detecting OGSR. Results were inconsistent and did not show a clear correlation between number of shots fired and detection of any of the target OGSR compounds. The adapted method did not show any overall improvement compared to the initial work. Methodologies used are described. 4 references, 2 figures, and 1 table

Date Published: July 1, 2017