Abstract: It is a new paradigm to use the likelihood ratio（LR） to express the same appraisal opinion. Although its basic logic is consistent with the traditional identification way, the two diverge in the appraisal basis and the quantification of the relationship between quantity and quality. The traditional identification is closely related to the formation process of the case evidence system. When resolving whether sequentially encountered objects originate from the same source and assessing probability, it relies on the condition of the identification material, the method and basis of the identification, and the internal logical analysis of cumulative evidentiary value from concordant/disconcordant features. However, there are deficiencies in the expression of quantitative and qualitative science. In the theory of the same identification object, the scientific cognition of the uncertainty across different identification objects remains insufficient. The certainty of identification objects such as DNA and fingerprints is strong, while the uncertainty of identification objects such as habits, tools and footprints is strong, which determines the difference between the expression of the LR applications. Meanwhile, all identification objects increase uncertainty due to formative changes, which also limits the LR implementation. Meanwhile, the requirement of the fact-finders for the appraisal opinion is definitive and actionable, but from the judgment value of LR, it will cause risks and is difficult to be adopted by the fact-finders. Therefore, the practice of forensic science should start from the overall logical structure of the case evidence system and the requirements of the fact-finder, reasonably deploy both the traditional paradigm and the new paradigm of LR, and resolve the conflict between the identification theory and judicial practice, so as to promote the development of forensic science and promote the accurate identification of the case facts.

Key words: case evidence system, appraisal on identity determination, relevance, likelihood ratio, conflict and adjustment, identification paradigm transition

摘要：  运用似然比表达同一认定鉴定意见是一种新的范式，其基本的逻辑与传统的同一认定方式是一致的，但两者在鉴定依据，以及量与质关系定性的量化方式上存在不同。传统同一认定与案件证据体系形成进程密切相关，在解决先后出现的客体是否同一以及可能性时，依赖鉴定材料的条件状况、鉴定的方法和依据、对符合点与差异点的价值总和之间的内在逻辑分析等来实现，但存在定量及定性科学表达方式的不足。在同一认定鉴定对象理论中，对不同鉴定对象不确定性的科学认知仍然存在不足，DNA、指纹等鉴定对象的确定性强，而习惯类、工具和足迹等鉴定对象的不确定性强，这决定了应用“似然比”表达之间的差别，同时所有的鉴定对象因形成性变化而增加了不确定性，也使得“似然比”表达受到限制。同时，事实认定者对待鉴定意见的要求是“明确”与“高效”，而从“似然比”裁判价值来看，其会造成诸多风险，难以被事实认定者所采纳。故法庭科学实践应从案件证据体系整体逻辑结构及事实认定者的要求出发，合理地选择适用传统范式和“似然比”新范式，化解鉴定理论与司法实践的冲突，从而促进法庭科学的发展，以促进案件事实的准确认定。

关键词: 案件证据体系, 同一认定鉴定, 相关性, 似然比, 冲突与调适, 鉴定范式转变