Forensic Science Service, 2920 Solihull Parkway, Birmingham Business Park, Birmingham B37 7YN, United Kingdom.
Forensic Sci Int. 2011 Apr 15;207(1-3):101-5. doi: 10.1016/j.forsciint.2010.09.006. Epub 2010 Oct 20.
The authors have published elsewhere a quantitative method for assessing weight of evidence in the case where a finger mark from a crime scene is compared with a control print taken from a single finger of a suspect. The approach is based on the notion of calculating a likelihood ratio (LR) that addresses a pair of propositions relating to the single finger that was the origin of the crime mark. In practice, things are rather different because the crime mark will not just be compared with a single finger from a suspect but with a set of prints from all of his/her fingers; likewise, when the mark is compared with a database, this will consist of ten print records from random individuals. It is clear that "finger propositions" are not realistic in this situation and we show how our approach may be generalised to address a pair of propositions that relate to the person that made the crime mark. It often is the case that information is present at the crime scene that enables some inference to be drawn relating to which of the offender's ten fingers left a particular mark of interest. This kind of inference may profitably be drawn into the formal analysis. We illustrate our approach with an example.
作者曾在其他地方发表过一种定量方法，用于评估在将犯罪现场的指纹与嫌疑人单指采集的控制指纹进行比较的情况下，证据的权重。该方法基于计算似然比（LR）的概念，针对与犯罪标记起源的单个手指相关的两个命题。实际上，情况要复杂得多，因为犯罪标记不仅要与嫌疑人的单个手指进行比较，还要与嫌疑人所有手指的一组指纹进行比较；同样，当将标记与数据库进行比较时，数据库将包含十个随机个体的指纹记录。显然，在这种情况下，“手指命题”不切实际，我们展示了如何将我们的方法推广到解决与制作犯罪标记的人相关的一对命题。在犯罪现场通常存在一些信息，可用于推断出留下特定感兴趣标记的罪犯的十个手指中的哪一个。这种推断可以有益地纳入正式分析。我们用一个例子来说明我们的方法。
