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

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.

Gunshot wounds: a review of firearm type, range, and location as pertaining to manner of death.

Many studies have examined the characteristics of gunshot wounds by manner of death; however, no published study has directly compared these characteristics for the different types of firearms. This study was designed to address that deficiency. Existing data sets of nonaccidental deaths by handguns, shotguns, and rifles were reviewed. The victim data were analyzed by age and sex of the victims, wound location, range of fire, manner of death, and type of firearm. Handguns were the most common firearm used in both suicides and homicides, followed by rifles and then shotguns. For both homicides and suicides, there were significant differences between the firearm types for age of victims, range of fire, and wound locations. Possible reasons for those differences are discussed. It is concluded that information about the type of firearm is crucial to have when examining the nature of a firearm injury and determining the manner of death.

Handgun wounds: a review of range and location as pertaining to manner of death.

Citizens of the United States own more firearms than those in any other country, and the majority of the firearms owned are handguns. Given such prevalence, surprisingly few studies have been published describing the characteristics of deaths due to handguns. To address this gap, nonaccidental handgun deaths examined at the Bexar County Medical Examiner's Office between 2000 and 2010 were reviewed. A total of 1450 cases were identified, including 797 suicides and 653 homicides. Age, range of fire, location of wound, and manner of death were analyzed. The average age of suicide victims (46.7 years) was found to be greater than that of homicides (34.3 years). Suicidal wounds tended to be contact wounds to the head; abdominal, extremity, back, and multiple wound locations were more common in homicides as were distant and intermediate wounds. Handgun wounds to the forehead, side of head, submental, and intraoral locations were significantly more common in suicide, whereas those to the face, apex of the head, and back of the head were more common in homicides. Where possible, likelihood ratios were calculated to determine relative likelihood of suicide or homicide for specific wound locations and ranges. While each death should be analyzed based on its unique circumstances and not solely its statistical probability, these data may help inform the pathologist's conclusions.