Discrimination of Falls and Blows in Blunt Head Trauma: A Multi‐Criteria Approach

Abstract

In the discrimination of falls versus blows, the hat brim line (HBL) rule is mentioned in several textbooks as the most useful single criterion. Recent studies, however, have found that the HBL rule is only moderately valid and that its use on its own is not recommended. The purpose of this 6-year retrospective study was to find additional individually useful criteria in the distinction of falls from blows. Overall, the following criteria were found to point toward blows: more than three lacerations, laceration length of 7 cm or more, comminuted or depressed calvarial fractures, lacerations or fractures located above the HBL, left-side lateralization of lacerations or fractures, more than four facial contusions or lacerations, presence of ear lacerations, presence of facial fractures, and presence of postcranial osseous and/or visceral trauma. Based on the most discriminating criteria, a decision tree was constructed to be potentially applicable to future cases.

Suicide by blunt head trauma – Two cases with striking similarities

“…The large number of scalp lacerations, as previously investigated by Kremer and Sauvageau, are more likely to result from blows than falls [6][7][8][9].…”

“…According to the HBL rule, a wound located above the HBL is more likely to result from a blow while a wound located inside the HBL is more often related to a fall [6][7][8]. In sharp contrast to homicidal blow, most lacerations form clusters on the vertex in these two cases.…”

The Sima de los Huesos Crania: Analysis of the cranial breakage patterns

“…There is forensic literature dealing with the different criteria to distinguish falls and blows caused in violent events (Guyomarc'h et al, 2010; Kremer et al, 2008;Kremer and Sauvageau, 2009). Cranial depressed fractures can be a consequence of accidents, although they are more likely to be the result of interpersonal violence (Guyomarc'h et al, 2010;Walker, 1989). Nevertheless, cranial injuries from recent human interpersonal altercations are primarily facial (Galloway, 1999), mostly occur above the "hat brim line", usually show several lacerations, and are predominant on the left side of the vault (Guyomarc'h et al, 2010;Kremer et al, 2008;Kremer and Sauvageau, 2009).…”

“…HBL (Fig. 3C) was defined as the area located between two lines parallel to a line inspired by the Frankfort horizontal plane (horizontal plane passing through right and left portion points and the left orbitale), the superior margin passing through the glabella (G line) and the inferior margin passing through the center of the external auditory meatus (EAM line) (Guyomarc'h et al, 2010;Kremer et al, 2008;Kremer and Sauvageau, 2009). According to the HBL rule, an injury located at the level where the brim of a hat would lie is more likely the result of a fall, while a blow would generally produce a wound above this line (Guyomarc'h et al, 2010).…”

Virtual anthropology and forensic identification using multidetector CT

“…Recent studies have yielded additional information and criteria that can be helpful to differentiate blows from a fall, even if some do not exclusively concern bone. [81][82][83] The following criteria were found to be suggestive of blows: more than three lacerations, laceration length of 7 cm or more, comminuted or depressed calvarial fractures, lacerations or fractures located above the hat brim line, left-side lateralization of lacerations or fractures, more than four facial contusions or lacerations, the presence of ear lacerations, the presence of facial fractures and the presence of post-cranial osseous and/or visceral trauma. In ballistic trauma, MSCT is helpful in determining criteria such as location of the projectile(s), determination of the direction of fire and entry and exit bone wounds.…”