Discriminating factors in fatal blunt trauma from low level falls and homicide

Determination of the manner of death is a major issue in forensic practice. Differentiating the injuries caused by falls from a low height from injuries due to the deliberate application of a blunt object can be difficult. A few studies suggested the use of certain criteria, such as the hat brim line rule, to help in differentiating between falls and blows. Unfortunately they are not consistent.

All autopsy cases from a 16-year period (1996-2012) were analyzed retrospectively. Three groups were defined: homicide cases (n = 31), sudden natural deaths involving a fall (n = 103), and accidental fall cases (n = 30). The three groups were statistically compared across a wide range of parameters including general characteristics, presence, and characteristics of different types of wounds (lacerations, deep bruises, fractures, intracranial trauma, and defense injuries) as well as their respective anatomical site.

There were marked differences in wounds between homicide and fall cases, e.g., wounds were more numerous and larger in homicides. We did not confirm the hat brim line rule as a reliable discriminating parameter. A simple and highly effective multivariate model was found, which included the presence of lacerations, deep bruises, and intracranial trauma.

This study underlines the importance of autopsy findings in providing an indication of the manner of death. Conversely, the limitations of the hat brim line rule have been highlighted.