Homicide or suicide? Gunshot wound interpretation: a Bayesian approach.

Abstract

Many studies have been published examining various features of fatal gunshot wounds such as type of firearm, range of fire, number of shots, and wound location as a way of determining between homicidal and suicidal deaths. Pathologists frequently have to give evidence in court, and may have their opinion about probable manner of death challenged or be questioned about how sure they can be. In the literature, the features are always discussed in isolation, but in practice, the pathologist has to consider such details in combination. Using pooled data from a systematic review to obtain large data sets, this study shows how Bayesian analysis can be applied to consideration of combined features and can thus provide a quantified degree of confidence to support the pathologist's opinion through the use of likelihood ratios. Case examples are provided to illustrate the impact of different features.