物证鉴定范式发展(五):人脸相似分数似然比范式  

Forensic Paradigm Development.Part 5:LR Paradigm of Facial Similarity Score

作　　者：王桂强 WANG Guiqiang(Institute of Forensic Science,Ministry of Public Security,Beijing 100038,China)

机构地区：[1]公安部鉴定中心,北京100038

出　　处：《刑事技术》2025年第2期111-123,共13页Forensic Science and Technology

摘　　要：人脸相似分数似然比范式是关于人脸比对分数结果证据意义解释的理论和方法,也是物证鉴定贝叶斯似然比范式的最新方法。人脸相似分数似然比(LR)是在通常分别代表控辩双方主张的两个对立命题下,基于人脸分数概率分布数据定量分配的人脸分数结果出现概率的比值。命题通常涉及犯罪现场人脸像是否来自已知身份嫌疑人的问题。人脸分数LR表达了人脸分数结果对控辩双方的人脸来源命题的相对支持方向和强度,为决策者确定有争议的人脸来源命题事实提供了量化的证据价值。决策者基于人脸分数LR意见,或基于LR经贝叶斯定律和先验几率导出的人脸来源命题后概率,结合案件其他证据排除合理怀疑地确定人脸来源事实。人脸相似分数LR范式在科学逻辑以及意见形成、表述、理解和推理应用方面完全不同于我们已经习惯的传统范式,与目前广泛应用的DNA特征LR范式也存在差异,这给鉴定人和决策者提出了新的要求和挑战。The likelihood ratio paradigm of facial similarity score is the theory and method for interpreting the evidential signifi cance of score fi nding from facial comparison.Facial similarity score likelihood ratio is the latest method of Bayesian likelihood ratio paradigm for forensic science.The likelihood ratio(LR)of facial similarity score is the ratio of the occurring probability of the facial score fi nding quantitatively assigned based on the probability distribution data of facial scores,under a pair of confl icting propositions that usually represent the claims of the prosecution and defense parties.The propositions typically deal with the question of whether a facial image with unknown identity collected at a crime scene comes from a suspect with known identity.The face score LR expresses the relative support direction and strength of the face score fi nding for the propositions of the prosecution and defense parties,providing quantitative evidence value for decision-makers to determine the disputed fact of the face source.The decision maker determines the fact of the facial source proposition based on the facial score LR opinion,or the posterior probability of the facial source proposition derived from the LR and the prior odds through Bayesian law,combined with other evidence,to exclude reasonable doubt.The likelihood ratio paradigm of facial similarity score is completely different from the traditional paradigm we are accustomed to in terms of scientifi c logic,opinion formation,expression,understanding,and reasoning applications.It also differs from the widely used LR paradigm of DNA feature fi ndings,which poses new requirements and challenges for forensic examiner and decision-makers.

关 键 词：物证鉴定 人脸 相似分数 分数似然比 范式 

分 类 号：DF794[政治法律—诉讼法学]