Centro de Documentação da PJ
Analítico de Periódico
CD 341
An algorithm for forensic toolmark comparisons [Recurso eletrónico] / Maria Cuellar, Sheng Gao, Heike Hofmann
Forensic Science International: Synergy, Vol. 9 (2024), [15] p.
Ficheiro de 14,8 MB em formato PDF.
IDENTIFICAÇÃO DE OBJECTOS, ANÁLISE LABORATORIAL, METODOLOGIAS, MARCAÇÃO DE OBJECTOS
Forensic toolmark analysis traditionally relies on subjective human judgment, leading to inconsistencies and lack of transparency. The multitude of variables, including angles and directions of mark generation, further complicates comparisons. To address this, we first generate a dataset of 3D toolmarks from various angles and directions using consecutively manufactured slotted screwdrivers. By using PAM clustering, we find that there is clustering by tool rather than angle or direction. Using Known Match and Known Non-Match densities, we establish thresholds for classification. Fitting Beta distributions to the densities, we allow for the derivation of likelihood ratios for new toolmark pairs. With a cross-validated sensitivity of 98 % and specificity of 96 %, our approach enhances the reliability of toolmark analysis. This approach is applicable to slotted screwdrivers, and for screwdrivers that are made with a similar production method. With data collection of other tools and factors, it could be applied to compare toolmarks of other types. This empirically trained, open-source solution offers forensic examiners a standardized means to objectively compare toolmarks, potentially decreasing the number of miscarriages of justice in the legal system.
