AFTE Store - Firearm and tool marks Identification: The Bayesian Approach

We have read with interest the paper written recently by Bruce Moran in the AFTE Journal and the exchange of letters in INTERface. The author is a respected commentator in the field of firearm and tool mark examination. He challenges readers to demonstrate the practical applicability of Bayes theorem in firearms and tool mark examination. Mr Moran discusses an +objective+ criterion such as consecutive matching striae (CMS) and it’s applicability to firearms and tool marks examination. Notably he suggests the adoption of the consecutive matching striae numerical criterion for identification which (in the author’s words) establishes a clear threshold between identification and non-identification in striated tool marks, because it is based on scientific principles and sound empirical research. He also declares that Bayes theorem is not appropriate as an effective means to interpret the identification science.