Gunshot residue (GSR) has been analyzed in forensic laboratories since 1933 when the dermal nitrate test originated. (1) Detection and analysis of GSR has since developed with the invention and implementation of instrumentation. Since the 1960s, inorganic gunshot residue (IGSR) has been the primary focus for GSR analysis. (2) As disadvantages like omitting lead from ammunition and the transient properties of IGSR are researched, it is clear that a new approach is needed. Organic gunshot residue (OGSR) analysis has the potential to become the novel approach for GSR analysis because OGSR does not have the same transient properties as IGSR. (3) The compounds are lipophilic and are therefore more likely to remain on the shooter’s hands or face. (4) OGSR can be analyzed through a myriad of instrumentations, including High Performance Liquid Chromatography/Mass Spectrometry(HPLC/MS). Analysis with HPLC/MS allows for customizable mobile phases, gradients, columns, and ionization to ensure the complete detection of OGSR. Using a Shimadzu Ultra Performance Liquid Chromatography (UPLC) coupled with an AB Sciex Q-Trap 4000 MS/MS, a method is optimized for the detection of Diphenylamine (DPA), Nitroglycerin (NG), and Ethyl Centralite (EC). The next steps for experimentation are summarized and include an elution study and a time-course study.

The three introductory chapters are intended to summarise the available knowledge prior to the experimental work and to provide useful background information for chemists, with little or no understanding of firearms, who are required to undertake the chemical aspects of firearms casework examination. Chapter 1 provides a much condensed outline of the historical development of firearms and ammunition, with emphasis on ignition systems up to the development of the percussion primer and self contained ammunition. The second chapter presents a comprehensive literature search on the chemical nature of modem ammunition and firearms, with particular attention to priming compositions and projectiles. The final introductory chapter deals with the nature and properties of firearms discharge residues and outlines the most important developments in the search for a satisfactory detection and identification method. The objective of the experimental work is to record experience gained from the 26 year terrorist campaign in Northern Ireland and to use such experience, coupled with further research and development, to substantially improve existing procedures for firearms and explosives residue detection. The experimental work conducted is detailed in Chapter 4. Chapter 5 deals primarily with the Particle Analysis method for the detection and identification of firearms discharge residue, particular attention being directed towards the particle classification system and discharge residue from mercury fulminate and Sintox primed ammunition. Chapter 6 covers suspect handling procedures and contamination avoidance and makes recommendations for permanent improvements in and regular monitoring of the environment in which suspects are sampled. Chapter 7 outlines the development of a method for the detection of the organic constituents of firearms discharge residues, which is compatible with existing inorganic firearms discharge residue and organic explosive residue detection techniques and which enables all suspects to be routinely screened for inorganic and organic firearms discharge residue and organic explosives residue. The final chapter summanses the conclusions, recommendations and comments arising from the work.

Thesis (M.S.)--California Polytechnic State University, 2010. / Mode of access: Internet. Title from PDF title page; viewed on April 14, 2010. Major professor: Dr. Lanny Griffin. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Biomedical Engineering." "April 2010." Includes bibliographical references (p. 73-75).

Thesis (M.S.)--Michigan State University. Forensic Science, 2008. / Title from PDF t.p. (Proquest, viewed on Aug. 12, 2009) Includes bibliographical references (leaves 74-76).

Made available in DSpace on 2018-08-01T21:58:49Z (GMT). No. of bitstreams: 1 tese_12216_Larissa Campos Motta.pdf: 5830957 bytes, checksum: bad711c20153d4ed1e56fd1b91ea34b7 (MD5) Previous issue date: 2018-03-28 / Considerando o grande aumento das mortes violentas, principalmente no Brasil, e a crescente utilização de armas de fogo para cometer tais crimes, a balística forense associada a entomologia forense se tornam grandes aliadas nas investigações criminais. As concentrações de chumbo (Pb), bário (Ba) e antimônio (Sb), caracerísticos de resíduos de disparo de arma de fogo (GSR GunShot Residue), foram monitoradas em larvas de moscas (imaturos de Chrysomya albiceps). As coletas sucederam em um cadáver de porco, do sexo feminino, morto com três disparos realizados com pistola Taurus®, calibre .40 a curta distância (entre 25 e 40 cm), sendo dois disparos na região cefálica e um na região abdominal, em um período de 2 a 12 dias após a morte, durante o inverno, sob a influência da chuva e alta umidade relativa do ar. Dessa forma, o objetivo deste trabalho foi avaliar a aplicabilidade da técnica de espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) para a quantificação de Pb, Ba e Sb proveniente de GSR em larvas cadavéricas num ambiente não controlado, simulando um caso real de homicidio. Foi possível detectar e quantificar os três elementos traço de interesse pela técnica proposta, onde as concentrações mantiveram-se praticamente constante durante o estágio de putrefação. Concentrações mínimas (Pb = 382,26 μg·L-1; Ba = 140,50 μg·L-1; Sb = 39,18 μg·L-1) e as concentrações máximas (Pb = 522,66 μg·L-1; Ba = 190,30 μg·L-1; Sb = 56,14 μg·L-1) foram encontradas durante o terceiro e quinto dia post mortem, respectivamente. As amostras também foram analisadas pelo teste colorimétrico usando rodizonato de sódio (reação Feigl-Suter) apresentando resultado negativo para todas as soluções obtidas a partir dos imaturos de Chrysomya albiceps. Uma hipótese para a constância nas concentrações dos três elementos, é que de acordo com a literatura, as larvas da espécie Chrysomya albiceps podem exercer papel como predadora intraguilda de larvas de outras espécies de Dípteras, além de realizar canibalismo. Sendo assim, a técnica de ICP OES apresenta maior sensibilidade na quantificação frente ao convencional teste colorimétrico, mostrando ser uma técnica aplicável a esse tipo de matriz. É importante notar que o desenvolvimento tal pesquisa é de grande importância forense e é uma técnica que apresenta potencial para aplicação futura em casos de morte violenta, em que a vítima se encontra em decomposição inicial, moderada e avançada. Nesse aspecto, o desenvolvimento e aperfeiçoamento de metodologias eficientes são de grande relevância para a elucidação de crimes.

All quantitative measurements have a degree of measurement uncertainty. While the term uncertainty can be essentially defined as doubt, measurement uncertainty in this sense instead inspires assurance in a quantitative value to a certain degree of confidence. Dating back to the advent of modern statistics in the 1700s, an international consensus on measurement uncertainty did not occur until the 1995 release of the Guide to the Expression of Uncertainty in Measurement (GUM), the fundamental document on the subject. The GUM was further adopted by major players in the field of measurement including the International Bureau of Weights and Measures (BIPM), National Measurement Institutes (NMI), and the International Organization for Standardization (ISO), and is used as the gold standard of documentary standards in labs around the country. Gunshot residue (GSR) patterns of distribution are used to establish a range of possible distances that the muzzle of the firearm was from the target in order to piece together a particular series of events. Using the firearm and ammunition that was involved in that particular crime, an analyst can perform test fires using fabric swatches attached to test panels at varying muzzle-to-target distances, generally every three to six inches between contact and 48 inches. This allows for the creation of comparable patterns of soot and GSR to the actual pieces of evidence. Because different distances can have considerably different residue patterns, it is important that a method for creating the test panels minimize uncertainty in order to be considered reliable and reproducible. When establishing a protocol for determining the measurement uncertainty in the creation of test panels, the two most important factors are the measuring device and a repeatability study. A measuring device, in this case a stainless-steel ruler, with metrological traceability reduces the measurement uncertainty because every value is reliable and traceable back to an original source. A repeatability study is then used to take numerous measurements over time under similar conditions. Using this data, statistical analysis can be applied to evaluate the standard deviations and uncertainties. A total of 238 measurements were taken by eight members of the Boston Police Department Crime Laboratory on eleven different days over the course of a month. The measurements were divided into eight baseline distances that the firing device, a Ransom Rest, had been set to: 3”, 6”, 9”, 12”, 18”, 24”, 36”, and 42”. The data was analyzed as a whole, as well as split into two groups: a group of four analysts who are proficient and authorized to perform GSR distance determination testing (Group A), and a second group of four analysts with no GSR distance determination training or experience (Group B). At a confidence interval of 95.45%, the reported uncertainty was found to be 0.082 inches for the total group, 0.045 inches for the group trained in performing GSR distance determination, and 0.043 inches for the group with no experience in distance determination testing. F-test statistical analysis of the standard deviations of each distance, along with a comparison of the uncertainties, indicates no significant difference between the abilities of the two groups and that it’s possible a new uncertainty of measurement will not be required when current GSR distance determination analysts leave or new analysts are hired and trained, given that all other variables remain constant. The outlined method and experiment for determining measurement uncertainty was successful in that it met the four main requirements set forward by the American National Standards Institute (ANSI) National Accreditation Board (ANAB): (a) include the specific measuring device or instrument used for a reported test result in the estimation of measurement uncertainty for that test method; (b) include the process of rounding the expanded uncertainty; (c) require the coverage probability of the expanded uncertainty to be a minimum of 95.45%; and (d) specify a schedule to review and/or recalculate the measurement uncertainty.

Noise-induced hearing loss and tinnitus are the two most prevalent service-connected disabilities for veterans receiving compensation (Department of Veterans Affairs, 2010). While it is possible to protect against noise-induced hearing damage with hearing protection devices (HPDs) and hearing protection enhancement devices (HPEDs), military personnel resist using HPDs/HPEDs that compromise their situational awareness, including ability to localize enemy gunfire. Manufacturers of a new generation of "pass-through" level-dependent HPEDs claim these devices preserve normal or near-normal hearing. A research study was conducted to evaluate localization of suprathreshold gunshot's report (from blank ammunition) with one passive (3M's Single-Ended Combat Arms earplug) and three electronic level-dependent HPEDs (Peltor's Com-Tac II electronic earmuffs and Etymotic's EB 1 and EB 15 High-Fidelity Electronic BlastPLG earplugs), in comparison to the open ear in an in-field test environment with ambient outdoor noise and in 82 dBA diesel truck noise with nine normal and four impaired hearing participants. Statistical analysis showed worse localization accuracy and response time with the Com-Tac II earmuffs than with the other tested HPEDs. Performance with all HPEDs was worse than that with the open ear, except on right-left confusions, in which the Com-Tac II stood alone as worst, and in response time, for which the EB 1 earplug was equivalent to the open ear. There was no significant main effect of noise level. There was generally no significant effect of hearing ability. However, participants with impaired hearing had more right-left confusions than those with normal hearing. Subjective ratings related to localization generally corroborated objective localization performance. Three follow-up experiments were performed: (1) an assessment of the effect of microphone position on localization with the EB 15, which showed a limited advantage when the microphone was positioned near the opening of the ear canal compared to when it was facing outwards; (2) an assessment of Etymotic's QuickSIN test as a predictor localization performance, which showed little correlation with localization performance; and (3) an assessment of the acoustic properties of the experiment site, which was inconclusive with regards to the direction of dominant sound energy from gunshots from each of the shooter positions. / Ph. D.

Gunshot residue (GSR) analysis is a crucial aspect of the investigation of firearms-related incidents. The presence of GSR on a person or surface can provide valuable insight regarding proximity or involvement of an individual in a shooting incident. Traditionally, GSR analysis relies on the detection of inorganic compounds within the ammunition, known as inorganic gunshot residue (IGSR). These inorganic compounds are comprised of lead, barium, and antimony. IGSR compounds originate from the content of the primer, and each individual element is expelled during discharge, fused while molten, and land on nearby surfaces. Stubs with an adhesive coat are used to collect these particles by pressing against a surface suspected to have GSR particles. The current analytical method for detection and identification of IGSR, Scanning Electron Microscopy and Energy Dispersive X-Ray Spectroscopy (SEM/EDS), surveys GSR stubs for both the elemental composition as well as the morphology of the compounds. Positive identification requires both the elemental composition and spherical morphology of IGSR. Several issues exist with the nature of IGSR as well as the current method of analysis. Identification by SEM/EDS not only requires time for transportation and labor but may also produce false negatives due to inconsistent shape or lack of all three elements. The development of a rapid and robust analytical technique would address these deficiencies. Mass spectrometry (MS) is a standard analytical technique known for its specificity and accuracy. New advancements in research and technology have produced the ability to miniaturize MS while retaining its superior capabilities in identification. The characteristics of IGSR also pose issues in terms of validity, such as specificity to discharging a weapon, and ability to be transferred or wiped off. Qualities such as these can lead to both false negatives and false positives. In recent years, advances in forensic science research have studied the composition of organic gunshot residue (OGSR) as well as new methods for detecting these compounds. Research has pointed towards advantages in OGSR that would rectify the analytical issues seen in using IGSR as the target compound. Some qualities of OGSR that would improve GSR detection are its specificity to GSR, the molecular complexity of its components, its higher persistence on surfaces, and lower transferability. This study addressed both issues by employing the MX908 High Pressure Mass Spectrometer and developing an analytical method for major OGSR targets. The objective of this research was to test the MX908’s ability to ionize and detect Nitroglycerin (NG), Diphenylamine (DPA), Ethyl Centralite (EC), Dibutyl Phthalate (DBP), and Nitroguanidine (NQ). Furthermore, these experiments tested a range of voltage parameters to achieve optimal fragmentation, and ultimately an accurate and specific analytical method.

Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendix: leaves 113-114. Includes bibliographical references (leaves 115-118).

Thesis (M.A.)--Texas State University-San Marcos, 2007. / Vita. Appendix: leaves 113-114. Includes bibliographical references (leaves 115-118).