Noblis, Inc, USA.
Federal Bureau of Investigation, Laboratory Division, Questioned Documents Unit, USA.
Forensic Sci Int. 2022 Oct;339:111418. doi: 10.1016/j.forsciint.2022.111418. Epub 2022 Aug 9.
The interpretation of footwear evidence relies on the expertise of forensic footwear examiners. Here we report on the largest study to date of the accuracy, reproducibility (inter-examiner variation), and repeatability (intra-examiner variation) of footwear examiners' decisions. In this study, 84 practicing footwear examiners each conducted up to 100 comparisons between questioned footwear impressions (provided as photographs and digital images) and known footwear (provided as photographs, transparent test impressions, and digital images), resulting in a total of 6610 comparisons. The quality and characteristics of the impressions were selected to be broadly representative of those encountered in casework. A multilevel conclusion scale was used: 40% of responses were definitive conclusions (identification or exclusion), 14% probable conclusions (high degree of association or indications of non-association), 40% class associations (association of class characteristics or limited association of class characteristics), and 6% neutral conclusions (inconclusive or not suitable). On nonmated comparisons, 0.2% of conclusions were erroneous identifications (false positives), and 1.4% were incorrect responses of "high degree of association." The majority of erroneous identifications were made by a single participant. On mated comparisons, 6.0% of conclusions were erroneous exclusions (false negatives), and 1.8% were incorrect responses of "indications of non-association." Erroneous conclusions were sometimes reproduced by different examiners, but rarely repeated by the same examiner-1.1% of erroneous identifications were reproduced (none were repeated) and 19.9% of erroneous exclusions were reproduced (just one was repeated). Examiners' assessments of whether a questioned impression was suitable for comparison were notably inconsistent and may benefit from standardization. Rates of correct definitive conclusions are directly associated with the quality of the questioned impression and the extent of class similarities/differences between the questioned impression and known footwear.
鞋类证据的解释依赖于法庭鞋类鉴定专家的专业知识。在这里，我们报告了迄今为止关于鉴定人员决策的准确性、可重复性（鉴定人员间的差异）和再现性（鉴定人员内的差异）的最大研究。在这项研究中，84 名执业鞋类鉴定人员每人对 84 个疑问鞋印（以照片和数字图像形式提供）与已知鞋类（以照片、透明测试印痕和数字图像形式提供）之间进行了多达 100 次比较，总共进行了 6610 次比较。印痕的质量和特征选择具有广泛的代表性，代表了在实际工作中遇到的情况。使用了多层次的结论量表：40%的反应是明确的结论（识别或排除），14%是可能的结论（高度关联或表明非关联），40%是类别关联（类别特征的关联或类别特征的有限关联），6%是中性结论（不确定或不适合）。在非匹配比较中，0.2%的结论是错误识别（假阳性），1.4%是“高度关联”的错误反应。大多数错误识别都是由一个参与者做出的。在匹配比较中，6.0%的结论是错误排除（假阴性），1.8%是“表明非关联”的错误反应。错误的结论有时会被不同的鉴定人员复制，但很少被同一名鉴定人员重复——1.1%的错误识别被复制（没有被重复），19.9%的错误排除被复制（只有一个被重复）。鉴定人员对疑问印痕是否适合比较的评估明显不一致，可能受益于标准化。正确的明确结论率直接与疑问印痕的质量以及疑问印痕与已知鞋类之间的类别相似性/差异程度有关。
