LIBRARY
HON 499: Professor Moon's Library Instruction (Dr. Duncan): YW
Searching the Catalog for Articles (Bullets AND Projectiles)
Firearms, bullets, and wound ballistics: an imaging primer.
A Calculation of the Theoretical Significance of Matched Bullets
| Author: | David Howitt Affiliation: Graduate Program in Forensic Science, Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616.; Fred Tulleners Affiliation: Graduate Program in Forensic Science, Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616.; Karen Cebra Affiliation: Graduate Program in Forensic Science, Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616.; Shiahn Chen Affiliation: Graduate Program in Forensic Science, Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616. |
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| Edition/Format: |  Article : English |
| Publication: | Journal of Forensic Sciences, v53 n4 (July 2008): 868-875 |
| Peer-reviewed | |
| Database: | Wiley Online Library |
| Other Databases: | ArticleFirst; British Library Serials; ECO; MEDLINE; Elsevier |
| Summary: |
Abstract: The comparison and identification of bullets from the striations that appear on their surfaces, after they have been fired from a gun, have been practiced since the 1920s. Although the significance of the correspondences of these impression marks has been empirically justified, there is a conspicuous absence of any theoretical foundation for the likelihood. What is presented here is the derivation of the formulae for calculating the probability for the correspondence of the impression marks on a subject bullet to a random distribution of a similar number of impression marks on a suspect bullet of the same type. The approach to the calculation entails subdividing the impression marks into a series of individual lines having widths equal to the separation distance at which a misalignment of striations between the two bullets cannot be distinguished. This distance depends upon the resolution limit imposed by the microscope as well as by the visual acuity of the examiner. A calculation of the probabilities for finding pairs and triplets of consecutively matching lines on nonmatching bullets, by an examiner with normal perception using a microscope at 40× magnification, produces values that agree well with the empirical probabilities determined by Biasotti in the 1950s and when determined for larger consecutive sequences suggest that they are extremely unlikely to occur. The formulae can be used to determine the probabilities for the random occurrence of any sequence of striae and provide a straightforward way to quantitatively justify the significance of a specific match between any two bullets.
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Automated bullet-identification system based on surface topography techniques
| Author: | F Xie Affiliation: Centre for Precision Technologies, University of Huddersfield, Huddersfield HD1 3DH, UK; S Xiao Affiliation: Centre for Precision Technologies, University of Huddersfield, Huddersfield HD1 3DH, UK; L Blunt Affiliation: Centre for Precision Technologies, University of Huddersfield, Huddersfield HD1 3DH, UK; W Zeng Affiliation: Centre for Precision Technologies, University of Huddersfield, Huddersfield HD1 3DH, UK; X Jiang Affiliation: Centre for Precision Technologies, University of Huddersfield, Huddersfield HD1 3DH, UK |
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| Edition/Format: | Article : English |
| Publication: | Wear, v266 n5-6 (20090315): 518-522 |
| Peer-reviewed | |
| Database: | Copyright 2016 Elsevier B.V. All rights reserved |
| Summary: |
Every firearm has individual characteristics that are as unique to it as fingerprints are to human beings. When a firearm is fired, it transfers these characteristics - in the form of microscopic scratches and dents - to the fired bullets and cartridge casings. The rifling of the barrel of the firearm marks the bullets travelling through it, and the firearm's breech mechanism marks the ammunition's cartridge casing. Characterising these marks is the critical element in identifying firearms.
Traditionally the comparison of ballistic evidence has been a tedious and time-consuming process requiring highly skilled examiners. In the past decade, engineers have created automated ballistics identification systems that meld traditional comparison microscopes with digital cameras, computers, huge databases, and image analysis techniques. This kind of system can help investigators to link crimes by automatically finding similarities among images of bullet but suffering significant drawbacks and minimal matching. More recently, approaches based on 3D digital representations of evidence surface topography have started to appear, both in research and industrial products. Potentially the introduction of 3D surface topography measurement can overcome the limitations of digital imaging systems by making the bullet surface measurement reproducible and reliable. A 3D quantitative approach for bullet identification is proposed in this paper. In this system the surface topography of the whole bullet can be acquired for analysis and identification. Primary researches have been done by applying advanced surface topography techniques for bullet marks’ characteristics extraction. A variety of 2D and 3D visualization graphics have also been provided to help firearm examiners to make final decisions. Read less |
books and ebooks
Ballistic Imaging by ISBN: 9780309117258Publication Date: 2008-09-10Ballistic Imaging assesses the state of computer-based imaging technology in forensic firearms identification. The book evaluates the current law enforcement database of images of crime-related cartridge cases and bullets and recommends ways to improve the usefulness of the technology for suggesting leads in criminal investigations. It also advises against the construction of a national reference database that would include images from test-fires of every newly manufactured or imported firearm in the United States. The book also suggests further research on an alternate method for generating an investigative lead to the location where a gun was first sold: "microstamping," the direct imprinting of unique identifiers on firearm parts or ammunition.
Forensic Ballistics in Court by ISBN: 1118505018Publication Date: 2013-03-11Forensic Ballistics in Court: Interpretation and Presentation of Firearms Evidence is an accessible introduction to firearms and ballistics evidence and how this is analysed and presented as evidence in a court of law. The book approaches the subject in terms of the realities of case work, opening with a clear and illustrated explanation of the correct nomenclature for various weapon types and their parts. Ammunition is also extensively covered, again with annotated illustrations. Basic external and terminal ballistics, wounding capabilities are likewise covered to give an overview of the subject. A key aspect of the book covers the theory and philosophy behind striation matches and the associated statistics, how positive matches should be peer reviewed and the importance accreditation has on this subject. Gunshot residue formation and identification and the various methods used in its analysis are reviewed in depth. This includes a critical examination of the pros and cons of each type of examination and the evidential weight which can be applied to each method. Accessible and reader-friendly introduction to firearms and ballistics. Clarifies the limitations of firearms evidence. Extensive use of global case-studies throughout. Focus on the interpretation and assessment of the weight of firearms/ballistics evidence presented at court. Covers the importance of witness and accused statements and their interpretation in relation to the investigation under review. Includes coverage of gunshot residue collection, examination and interpretation and the potential for contamination of GSR samples. Includes numerous real life case studies that the author has dealt with over the past 45 years. Takes an applied approach to the subject.
