Estimate of the random match frequency of acquired characteristics in footwear: Part I — Impressions in blood

IF 1.9 4区医学 Q2 MEDICINE, LEGAL

Science & Justice Pub Date : 2024-01-01 DOI:10.1016/j.scijus.2023.10.005

Alyssa N. Smale, Jacqueline A. Speir

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Abstract

The aim of this study was to estimate random match frequency of randomly acquired characteristics (RAC-RMF) for laboratory-simulated crime scene impressions. Part I of this investigation reports this metric using a dataset of more than 160 questioned impressions created in blood and deposited on tile. A total of 759 RACs were identified in the blood impressions and compared to RACs with positional similarity in test impressions from 1,299 unrelated outsoles. Geometric similarity was quantified using a combination of visual comparisons and mathematical modeling based on percent area overlap. Results indicated that RACs in blood impressions were typically smaller, and therefore exhibited a two-thirds increase in the number of indistinguishable pairs compared to their mated test impressions. For shoes contributing at least one RAC, relative RAC-RMF values $⩾$ 0.0008 were encountered at a rate between 3.4% and 34% for the blood impressions examined in this study. Part II of this investigation provides analogous results based on dust impressions deposited on paper and tile. Although the results in Part I and Part II are specific to randomly acquired characteristics and do not translate into an impression-wide RMF estimate, this research shows that RACs in questioned impressions of the type expected in casework co-occur in position and geometry with RACs in non-mated test impressions. Since theoretical models have traditionally been the basis for estimating RAC-RMF in footwear, the overall contribution of this research to the forensic footwear community is a calibration of this estimate based on empirical data.

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鞋类后天特征随机匹配频率的估计：第一部分 - 血液印迹

本研究旨在估算实验室模拟的犯罪现场印痕的随机匹配频率（RAC-RMF）。本次调查的第一部分使用了一个数据集，该数据集包含 160 多个经质疑的血印，这些血印沉积在瓷砖上。在血印中总共识别出 759 个 RAC，并将其与 1299 个无关外底测试印迹中位置相似的 RAC 进行比较。通过视觉比较和基于重叠面积百分比的数学建模相结合的方法，对几何相似性进行了量化。结果表明，血印中的 RAC 通常较小，因此与配对的测试鞋印相比，无法区分的鞋对数量增加了三分之二。对于至少有一个 RAC 的鞋来说，在本研究中检测的血印中，RAC-RMF 相对值⩾ 0.0008 的比率介于 3.4% 和 34% 之间。本调查的第二部分根据沉积在纸张和瓷砖上的灰尘印迹提供了类似的结果。虽然第一部分和第二部分的结果是针对随机获得的特征，并不能转化为整个印模的 RMF 估计值，但这项研究表明，在个案工作中预期会出现的受质疑印模中的 RAC 与非配对测试印模中的 RAC 在位置和几何形状上是共存的。由于理论模型历来是估算鞋类 RAC-RMF 的基础，本研究对法医鞋类界的总体贡献在于根据经验数据校准了这一估算值。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Science & Justice 医学-病理学

CiteScore

4.20

自引率

15.80%

发文量

审稿时长

81 days

期刊介绍： Science & Justice provides a forum to promote communication and publication of original articles, reviews and correspondence on subjects that spark debates within the Forensic Science Community and the criminal justice sector. The journal provides a medium whereby all aspects of applying science to legal proceedings can be debated and progressed. Science & Justice is published six times a year, and will be of interest primarily to practising forensic scientists and their colleagues in related fields. It is chiefly concerned with the publication of formal scientific papers, in keeping with its international learned status, but will not accept any article describing experimentation on animals which does not meet strict ethical standards. Promote communication and informed debate within the Forensic Science Community and the criminal justice sector. To promote the publication of learned and original research findings from all areas of the forensic sciences and by so doing to advance the profession. To promote the publication of case based material by way of case reviews. To promote the publication of conference proceedings which are of interest to the forensic science community. To provide a medium whereby all aspects of applying science to legal proceedings can be debated and progressed. To appeal to all those with an interest in the forensic sciences.