title: Firing distance estimation based on the analysis of GSR distribution on the target surface using ICP-MS--an experimental study with a 7.65 mm × 17 mm Browning pistol (.32 ACP).
abstract: An experimental study aiming to estimate the firing distance was conducted using a 7.65 mm × 17 mm Browning (.32ACP) pistol. Briefly, test shots were made against a target of cotton tissue (35 cm × 35 cm), and the amounts of antimony (Sb), barium (Ba), and lead (Pb) deposited in quadrangular pieces (1 cm × 1 cm) of the target cut from four radial positions at increasing distances from the bullet entrance hole ("samples") were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The data obtained were used to search for a mathematical model for estimating the firing distance. The best model was a simple linear correlation between FD (the firing distance) and ln c (where c is the content of Sb, Ba or Pb in the samples, expressed in μg/g of target tissue). Best results were obtained with samples collected at radial distances within 2.0-3.0 cm from the bullet entrance hole. Using this approach, it was possible to accurately (±6 cm) estimate the firing distance in the interval [20-90] cm from the target.
authors.affiliation: National Institute of Legal Medicine and Forensic Sciences, North Branch, Jardim Carrilho Videira, 4050-167 Porto, Portugal; CENCIFOR - Forensic Science Center, Largo da Sé Nova, s/n, 3000-213 Coimbra, Portugal; Faculty of Medicine, Porto University, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; School of Health Sciences, Minho University, Campus Gualtar, 4710-057 Braga, Portugal. Electronic address: asantosinml@yahoo.com.
authors.forename: Agostinho
authors.initials: A
authors.lastname: Santos
authors.affiliation: REQUIMTE, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Ramos
authors.affiliation: Faculty of Medicine, Porto University, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Fernandes
authors.affiliation: National Institute of Legal Medicine and Forensic Sciences, North Branch, Jardim Carrilho Videira, 4050-167 Porto, Portugal; CENCIFOR - Forensic Science Center, Largo da Sé Nova, s/n, 3000-213 Coimbra, Portugal; Faculty of Medicine, Porto University, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; School of Health Sciences, Minho University, Campus Gualtar, 4710-057 Braga, Portugal; Biomedical Sciences Institute Abel Salazar, Porto University, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Magalhães
authors.affiliation: REQUIMTE, Department of Chemical Sciences, Laboratory of Applied Chemistry, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
authors.forename: Agostinho
authors.initials: A
authors.lastname: Almeida
authors.affiliation: Superior Institute of Engineering, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 431, 4200-072 Porto, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Sousa
keywords: Firing distance; Gunshot residues; ICP-MS; Sb, Ba and Pb analysis