Use of a gold microelectrode for discrimination of gunshot residues

• Published in: Sensors and actuators. B, Chemical Vol. 166-167; pp. 848 - 852
• Main Authors: Salles, Maiara O., Bertotti, Mauro, Paixão, Thiago R.L.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.05.2012
• Subjects: Actuators; Ammunition; Chemometrics; cluster analysis; crime; Discrimination; Electronic tongue; Firearm; Gold; Guns; hands; methodology; Microelectrodes; Pattern recognition; principal component analysis; Residues; Small arms; Voltammetry; Weapon discrimination; Firearm; Voltammetry; Electronic tongue; Pattern recognition; Weapon discrimination; Chemometrics
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2012.02.097

Gunshot residues (GSR) can be used in forensic evaluations to obtain information about the type of gun and ammunition used in a crime. In this work, we present our efforts to develop a promising new method to discriminate the type of gun [four different guns were used: two handguns (0.38 revolver and 0.380 pistol) and two long-barrelled guns (12-calibre pump-action shotgun and 0.38 repeating rifle)] and ammunition (five different types: normal, semi-jacketed, full-jacketed, green, and 3T) used by a suspect. The proposed approach is based on information obtained from cyclic voltammograms recorded in solutions containing GSR collected from the hands of the shooters, using a gold microelectrode; the information was further analysed by non-supervised pattern-recognition methods [(Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA)]. In all cases (gun and ammunition discrimination), good separation among different samples in the score plots and dendrograms was achieved.