Incomplete decapitation with exenteration of the brain in a motorcyclist run over by a semitrailer.

Although decapitation is a well-known traumatic mechanism in road traffic deaths, incomplete decapitation of a motorcyclist with exenteration of the brain has not yet been reported in the forensic literature in a victim run over by a vehicle. This paper deals with an autopsy case of a 69-year-old motorcyclist, who had been run over by a semitrailer, as a result of which flattening of the head with extrusion of the brain and incomplete decapitation occurred at the level of the fourth cervical vertebra. This constellation allows to define a special mechanism of accident-related decapitation. Moreover, the case underlines the importance of a multidisciplinary approach for the reconstruction of the accident as well as for the assessment of its judicial consequences. On the suspicion of a hit-and-run accident, simulation tests were performed by technical experts. These tests revealed that the motorcycle may not have been conspicuous for the truck driver prior to and during the accident. Consequently, the charge of manslaughter and failure to render assistance against the truck driver was dropped.