The missing chance of identifying the blade that produced a stab wound among different knives

BACKGROUND: One of the main goals of a forensic autopsy is to identify weapons causing injuries used in violent crimes. In this experimental study, a questionnaire was administered to 80 forensic pathologists.METHODS: The questionnaire included photos of 10 knives and 40 stab wounds that were produced on human limbs using four penetration-extraction patterns, and the pathologists were asked to match each wound to the specific knife. The aim of this study is to estimate the accuracy of diagnosing wound-weapon compatibility assessing the wound macroscopic features.RESULTS: Respondents correctly identified the knife in only a 13.1% of cases. The serrated-blade knives and the “perpendicular penetration-extraction” manner of production were more frequently associated to the related wound. Forensic pathologists with 1-3 years of experience were found to associate the correct weapon to the related wound more frequently than pathologist with longer experience.CONCLUSIONS: Our study confirmed that diagnosing wound-weapon compatibility remains an extremely complex process, as historically reported in general statements found in forensic textbooks and papers reporting forensic casework. Confounding factors are usually related to the high number of variables at stake in the production each stab wound, such as movements of the blade which especially in real cases remain almost undetermined. A promising avenue for future research lies in the potential application of artificial intelligence to develop algorithms that enhances the probability of accurately establishing the connection between weapon and wound, especially considering real case, involving a high number of stab wounds which must be comprehensive evaluated.