Rachel Bolton-King

Preventing miscarriages of justice: A review of forensic firearm identification

The role of a firearm examiner is wide ranging, involving tasks that require scientific understanding in aspects of chemistry, physics and biology. This article aims to provide a critical review of the key scientific principles and practices specifically involved with forensic firearm identification and to discuss how misidentifications have resulted in cases of injustice. Implementation of quality assured examination practice, demonstration of individual examiner competence and more objective methods of reporting are being adopted by firearm examiners and laboratories to address some of the criticisms relating to subjectivity and standardisation inherent within the discipline. The impact of these changes is outlined and further recommendations are made for both examiners and legal professionals to minimise the potential for future injustices involving firearms evidence. Latest research in the field is cited, continuing to support the theory and use of firearm identification as admissible evidence in court.

Numerical classification of curvilinear structures for the identification of pistol barrels

This paper demonstrates a numerical pattern recognition method applied to curvilinear image structures. These structures are extracted from physical cross-sections of cast internal pistol barrel surfaces. Variations in structure arise from gun design and manufacturing method providing a basis for discrimination and identification. Binarised curvilinear land transition images are processed with fast Fourier transform on which principal component analysis is performed. One-way analysis of variance (95% confidence interval) concludes significant differentiation between 11 barrel manufacturers when calculating weighted Euclidean distance between any trio of land transitions and an average land transition for each barrel in the database. The proposed methodology is therefore a promising novel approach for the classification and identification of firearms.