Particle Analysis for the Detection of Gunshot Residue. II: Occupational and Environmental Particles

Wolten, G. M.; Nesbitt, R. S.; Calloway, A. R.; Loper, G. L.

doi:10.1520/jfs10849j

Cited by 71 publications

(58 citation statements)

References 2 publications

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“…PIXE detects small quantities of a number of different elements (including Sn, Al, Si, Cl, Ca, and Zn) that are not detected by SEM-EDS. It is known from previous studies that certain gunshot residues can contain these elements [2]. In agreement with the SEM-EDS measurement, the measured K content of the pistol residue is higher than for the shotgun residue.…”

Section: Resultssupporting

confidence: 88%

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Trace element profiling of gunshot residues by PIXE and SEM‐EDS: a feasibility study

2009

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We critically compare particle induced X-ray emission (PIXE) on the ion microprobe with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) for the characterisation of gunshot residues (GSR). Samples of gunshot residue from several different firearms were collected. Individual particles of GSR were analysed by SEM-EDS using a 30keV electron beam focussed to ~10nm and PIXE using a 2.5MeV proton beam focussed to ~4 microns. PIXE revealed trace or minor elements undetectable by SEM-EDS, and could discriminate GSR indistinguishable by SEM-EDS. Introduction In order to demonstrate that a suspect in a criminal investigation has fired a weapon, police authorities routinely take swabs from the clothing, skin and hair of the suspect and use electron microscopy to search for gunshot residue (GSR) particles on the swabs. These particles are condensation products of the high temperature, high pressure reactions that occur when a firearm is fired and are known to be deposited at the crime scene and on the shooter [1]. The particles are made up of material from the primer, bullet, bullet jacket, cartridge casing and the gun barrel, are spherical, and are of the order of a few microns in diameter. There are several types of particle that are characteristic of gunshot residue, including those containing Pb, Ba and Sb [2].

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Section: Resultssupporting

confidence: 88%

“…The particles are made up of material from the primer, bullet, bullet jacket, cartridge casing and the gun barrel, are spherical, and are of the order of a few microns in diameter. There are several types of particle that are characteristic of gunshot residue, including those containing Pb, Ba and Sb [2]. …”

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confidence: 99%

Trace element profiling of gunshot residues by PIXE and SEM‐EDS: a feasibility study

2009

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Section: Introductionmentioning

confidence: 99%

“…With respect to this, studies have confirmed that, in the majority of cases, people with automobile-related jobs such as mechanics (batteries, motors, tyres), automotive electricians, users of cartridge-operated industrial tools, and people who work with fireworks have been shown to have higher levels of Ba, Pb and Sb on their hands, which, in some cases, may cause "false-positive" results. 2,3,7,8 For criminal justice, however, evidence of gunshot residue is only taken into consideration when "unique" GSR particles with the following elemental compositions: (1) Pb-Ba-Sb, (2) Sb-Ba or (3) Pb-Ba-Ca-Si-Sn are found.Chemical tests, based on color reactions to identify suspects at crime scenes, such as the "dermal nitrate test", 9 Griess reagent 10 and sodium rhodizonate, 11 but due to numerous incidences of false positive results these tests were abandoned by forensic scientists. Nowadays, the investigation of gunshot residue particles in forensic laboratories is usually performed by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), 12,13 using the tape-lift method for sample collection.…”

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confidence: 99%

Gunshot residues: screening analysis by laser-induced breakdown spectroscopy

Silva¹,

Cortez²,

Pasquini³

et al. 2009

J. Braz. Chem. Soc.

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A espectroscopia de emissão em plasma induzido por laser (LIBS) foi avaliada para a detecção de resíduos de disparo de arma de fogo (GSR) nas mãos de um suspeito. Para desenvolver o procedimento, 114 amostras foram obtidas pressionando um pequeno pedaço de fita adesiva contra a região dorsal das mãos de não-atiradores, atiradores após o disparo e de atiradores após terem lavado as mãos com sabão e água. As fitas foram analisadas diretamente em um equipamento LIBS baseado em um policromador echelle com resolução temporal construído em laboratório. Os espectros foram obtidos a partir da aplicação de um único pulso de laser em 20 locações diferentes, espalhadas uniformemente sobre a superfície da fita, para assegurar uma amostragem eficiente na detecção de resíduos de disparo. Os espectros mostram uma assinatura com linhas de emissão características de bário e chumbo. Quando os dados espectrais foram submetidos à técnica de reconhecimento de padrão SIMCA (Modelagem Independente e Flexível por Analogia de Classe), atiradores e não-atiradores foram corretamente classificados. O método baseado em LIBS e SIMCA demonstrou ser não-destrutivo da evidência do crime e permitiu discriminar as amostras coletadas de voluntários não-atiradores e atiradores, mesmo após a lavagem das mãos.Laser induced breakdown spectroscopy (LIBS) is further developed for the detection of gunshot residue (GSR) on the hands of a suspected shooter. To develop the procedure, 114 samples were obtained by pressing a small piece of adhesive tape against the dorsal region of the hands of nonshooters, of shooters just after firing a weapon, and of shooters after washing their hands with soap and water. The tapes were analyzed directly in a time-resolved echelle based LIBS system, assembled in the laboratory, and 20 single laser pulses, spread uniformly on the tape surface, were shown to be enough to ensure the detection of true positives. The spectra obtained by LIBS from the tape present a signature with emission lines that are attributed to barium and lead. After the spectral data was submitted to a pattern recognition method SIMCA (Soft Independent Modeling of Class Analogy), shooters and non-shooters were corrected classified. The method based on LIBS and SIMCA has been demonstrated to be non-destructive of crime evidence and enabled discrimination between the samples collected from non-shooter volunteers and shooter volunteers before and after washing their hands.Keywords: laser-induced breakdown spectroscopy, gunshot residues, SIMCA, screening analysis, LIBS IntroductionGunshot residues (GSR) evidence has been considered essential during recent decades in forensic science as it makes it possible to determine if a suspect has fired, been in crime location or come into contact with a firearm.Despite the recent advances in the production of the so called clean ammunitions and well sealed guns, the use of cheap and widespread standard fire arms and propulsive charge remains associated with the majority of hand-armed crimes.1 At the moment of shooting ...

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“…1 Based on SEM C EDS analysis, particles are classified 2,3 as 'unique' GSR or 'consistent' with GSR nature. For particles of the former type, SEM C EDS represents an exhaustive means to ensure their classification.…”

Section: Introductionmentioning

confidence: 99%

Microchemical and micromorphological features of gunshot residue observed by combined use of AFM, SA‐XPS and SEM + EDS

D'Uffizi¹,

Falso²,

Ingo

et al. 2002

Surface & Interface Analysis

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Microchemical and micromorphological analytical methods have been used by law enforcement agencies to ascertain whether or not an individual has been involved recently in a firearm shooting by determining the presence of gunshot residue (GSR).In the present work, the microchemical and micromorphological features of the GSR particles deposited on the bullet and on the firing hands, collected using double-sided tape, have been studied by means of the combined use of scanning electron microscopy + energy-dispersive spectroscopy (SEM + EDS), atomic force microscopy (AFM) and selected-area x-ray photoelectron spectroscopy (SA-XPS).The results indicate that this advanced approach could disclose new micromorphological and microchemical features that could be useful for considerably increasing the confidence level of such determination.

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Particle Analysis for the Detection of Gunshot Residue. II: Occupational and Environmental Particles

Cited by 71 publications

References 2 publications

Trace element profiling of gunshot residues by PIXE and SEM‐EDS: a feasibility study

Trace element profiling of gunshot residues by PIXE and SEM‐EDS: a feasibility study

Gunshot residues: screening analysis by laser-induced breakdown spectroscopy

Microchemical and micromorphological features of gunshot residue observed by combined use of AFM, SA‐XPS and SEM + EDS

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