Sharp force fatalities: Differentiating homicide from suicide through a retrospective review (2012–2019) of autopsy findings in Lisbon (Portugal)

•The usual homicide victim’s profile was a young foreign male found outdoors, with no weapon nor known mental illness.•Homicide victims presented thoracic and neck stab wounds and greater involvement of posterior and right-sided aspects.•Suicide victims presented neck and upper limb cut wounds, with the anterior and left-sided aspects being most affected.•Clothing damage, additional lesions, injured lungs or bone/cartilage and the presence of alcohol suggested homicide. Sharp force fatalities may have a homicidal, suicidal or accidental manner of death. To aid in such differentiation this study aimed to identify medico-legal elements which were predictors of a given manner of death as well as to describe the characteristics of these deaths. A retrospective review was performed on all homicides and suicides due to sharp force injury admitted at the South Branch of the National Institute of Legal Medicine and Forensic Sciences between January 2012 and December 2019. Deaths with a performed external examination or forensic autopsy and with available demographic, circumstantial or necroscopic information were included. Each case was reviewed to collect said information and inferential analysis was employed with both parametric and non-parametric tests as well as binary logistic regression to identify independent predictors, with significance defined at α = 0.05. A total of 57 homicides and 20 suicides were identified, with the obtained demographic and circumstantial profile of the homicide victim being that of a young foreign male whose body was found outside home, with no weapon nearby and without a known psychiatric background. Homicides presented more prominently stab wounds, with these being conspicuous on the thorax and neck. Conversely suicides notably presented cut wounds, being critically present in the neck and upper limbs. Oblique thoracic stab wounds conveyed a homicidal death. Other findings that suggested homicide included the presence of clothing damage, additional traumatic lesions and injured lungs or bone/cartilage. Toxicologically, alcohol presence was associated with homicides while psychiatric drugs suggested suicide. The logistic regression identified the presence of additional traumatic lesions (OR 14.8, p = 0.032) and the absence of lethal neck (OR 0.109, p = 0.043) and lethal upper limb (OR 0.022, p = 0.015) wounds as independent autopsy predictors of a homicidal death. However, no single feature is infallible in establishing manner of