Ballistics Image Processing and Analysis for Firearm Identification

Firearm identification is an intensive and time-consuming process that requires physical interpretation of forensic ballistics evidence. Especially as the level of violent crime involving firearms escalates, the number of firearms to be identified accumulates dramatically. The demand for an automatic firearm identification system arises. This chapter proposes a new, analytic system for automatic firearm identification based on the cartridge and projectile specimens. Not only do we present an approach for capturing and storing the surface image of the spent projectiles at high resolution using line-scan imaging technique for the projectiles database, but we also present a novel and effective FFT-based analysis technique for analyzing and identifying the projectiles

An Online Ballistics Imaging System for Firearm Identification

Since the traditional ballistics imaging system is dependent upon the expertise and experience of end-user, an intelligent ballistics imaging system is highly demanded to overcome the drawbacks of traditional techniques. This paper aims to develop a novel ballistics imaging system so as to combine the traditional functions with new features such as the line-scan image module, the characteristics extraction module, and the intelligent image processing module. With the help of these features, the new system can identify firearm more efficiently and effectively than the traditional techniques

Australian firearm identification system based on the ballistics images of projectile specimens

Charactetistic markings on the cartridge case and projectile of a fired bullet are created when it is fired. Over thirty different features within these marks can be distinguished, which in combination produce a fingerprint for a firearm. By analyzing features within such a set of fireann :fingerprints, it will be possible to identify not only the type and model of a fireann, but also each every individual weapon as effectively as human :fingerprint identification. A new analytic system based on fast Fourier transform (FFT) for identifying the projectile specimens by the line-scan imaging technique is proposed in this paper. Experimental results show that the proposed system can be used for firearm identification efficiently and precisely through digitizing and analyzing the fired projectiles specimens

Firearms and Ballistics

Chapter 7 of the book entitled 'Practical Veterinary Forensics' aims to introduce forensic veterinarians to the scientific concepts underpinning the field of firearms and ballistics. This introduction will enable practitioners to understand wound formation depending on the firearm and ammunition used. Various types of firearms, modern firing mechanisms and ammunition will be explained, together with an introduction to the physical concepts underpinning the four main constituents of the term ballistics; internal, intermediate, external and terminal ballistics. Wound ballistics is a sub-set of terminal ballistics and is specifically discussed to put the physical and chemical scientific concepts into context of forensic veterinary practice. The collection of firearms evidence from an animal and the surrounding crime scene is also considered to explain to practitioners the importance of sending this evidence for further forensic examination and analysis

An intelligent imaging approach to the identification of forensic ballistics specimens

The characteristic markings on the cartridge and projectile of a bullet fired from a gun can be recognised as a fingerprint for identification of the firearm. Over thirty different features can be distinguished. The intelligent imaging of the class characteristics of ballistics specimens will provide the potential to identify the make and model of the firearm. Precise measurement of features allow ballistics metrics to be obtained for the identification of the weapon. This paper will describe progress in the development of a multidimensional cluster analysis model for forensic ballistics specimens. The cluster analysis will provide classification that is based on scalar shape and measurement parameters for the 3D features of class characteristics. The selection of appropriate class characteristics for cartridge and projectile can be mapped in N-dimensional space to provide clustering for particular weapon types. By mapping the crime scene specimen to the multidimensional ballistics data, the possibility of a match for identification can be achieve

Correlation of distance and damage in a ballistic setting

Forensic Investigation is a discipline which relies on various fields in order to be able to reconstruct an incident. Forensic Ballistics focuses upon the mechanics of projectile launch, flight and the effects of the projectile when impacting a target as well as firearms and ammunition. One of the most common evidence types in firearms related events is Gun Shot Residue (GSR), where typical analysis methods involves chemical confirmatory tests. Therefore, the fields traditionally associated with forensic ballistics are chemistry and physics, however there are various other scientific fields which could potentially further knowledge in this area such as radiography and computational science. Arguably one of the most important considerations within Forensic Ballistics is the ability to accurately reconstruct an incident. Currently there is limited literature aimed at understanding GSR spread at distances above 15 metres, which is a limitation for the criminal justice system (chapter 1). This work aims to further this knowledge by gaining an understanding of GSR spread at various distances, both short and long range (chapter 4), whilst combining this with Gun Shot Wound (GSW) damage using radiography (chapter 3). The data obtained will then be used for computational modelling with the aim of predicting shooter distance (chapter 5)

Image matching of firearm fingerprints

A spent cartridge case exhibits characteristic markings (firearm fingerprint) that can be used to identify the type and possibly make of weapon in which the cartridge was fired. This report details research into the use of discriminant analysis for the purpose of matching spent rim-fire cartridge cases to specific make and model firearms. The discrimination and classification are based on several scalar shape parameters for the two-dimensional silhouette of the firing pin (FP) impression-- shape factor calculated from the second order moment of inertia, G factor calculated from the distance transform, and the P2A factor- as well as the distance between the centre of the cartridge case and the centroid of the FP impression, and the orientation of the principal centroidal axes associated with the FP impression. Classification results for two case studies are detailed: (i) 3 different make/model weapons producing different shaped FP impressions, and (ii) 5 different make/model weapons each producing a rectangular FP impression

Forensic Gunshot Residue Distance Determination Testing Using Identical Make and Model Handguns and Different Ammunitions.

The determination of how far a firearm was from a victim or target when it was discharged is a frequent request to crime laboratories. This determination requires test firing the firearm at various distances to compare gunshot residue patterns made during the test with patterns on the victim or target. Crime laboratories stipulate that the same firearm and ammunition used in commission of the crime must be used for this testing; however, little empirical evidence exists supporting this requirement. It was the purpose of this study to determine if there were any significant differences using different firearms and different ammunition in distance determination testing. The findings indicated that no significant differences occurred with different firearms but there were significant differences with different brands of ammunition