A Forensic Epidemiological Perspective on Single Stab Injuries to the Trunk in Surviving Assault Victims

Introduction The evidence base for assessing whether a single stab injury to the trunk was inflicted by another person in an assault or self-inflicted is mostly derived by studying autopsy populations. However, by studying characteristics in surviving victims of assaults, other factors of importance might be discernable. Methods and materials Surviving victims of assaults with single stab injuries to the trunk were identified utilizing a registry with all cases of clinical forensic medicine assessed by the Swedish National Board of Forensic Medicine in the year 2016. As reference groups, we also included homicides and suicides following single stabs to the trunk using the Swedish forensic autopsy register for the years 2010 to 2021. We extracted demographics, crime circumstances, and injury characteristics. The data was analyzed using Chi-square test, Fisher´s exact test and Mann-Whitney U test. Results We identified 83 surviving victims of assaults to be compared with 94 homicides and 45 suicides. The populations of assaults and homicides showed similar proportions of gender distribution (90.4 vs. 92.6 % males) and median age (31 years vs. 33 years). The suicide population was also male dominated (82.2 %), but with a significantly higher median age (52 years) (p < 0.001). Assaults and homicides were associated with an outdoor location (59.7 vs. 54.3 %), without a nearby sharp force instrument (75.9 vs. 69.1 %). In contrast, most suicides occurred in the victim’s own home (79.5 %) with a sharp force instrument observed in association with the body in nearly all cases (95.6 %). A similar proportion of cases with defensive wounds were seen in assaults and homicides (10.8 vs. 10.6 %). The ratio of entrance injury to the thorax in relation to abdomen was significantly lower in survivors of assaults (1.2) compared to homicides (3.3) (p = 0.002) and compared to suicides (2.8) (p = 0.04). Discussion and conclusion The demogra