Lethal mechanisms in cases of inverted suspension from the lap component of seat belts.

A retrospective review of autopsy files at Forensic Science South Australia in Adelaide, Australia, was undertaken over a five-year period from January 2014 to December 2018 for all motor vehicle crashes with rollovers ending with the vehicle inverted and the occupants suspended by the lap component of their seat belts. There were five cases, all male drivers (aged 18-67 years; Mage = 32 years). Acute neck flexion or head wedging was noted in four cases, with facial petechiae in four and facial congestion in one. Deaths were due to positional asphyxia in four cases, with the combined effects of positional asphyxia and head trauma accounting for the remaining case. Although all drivers had evidence of head impact which may have caused incapacitation, in only one case was this considered severe enough to have contributed to death. A blood alcohol level above the legal limit for driving was detected in two cases, but no other drugs were detected. This series demonstrates another subset of cases of seat belt-associated deaths where suspension upside down by the lap component of a seat belt had occurred after vehicle rollovers. Predisposing factors include incapacitation of the victim and delay in rescue. The postulated lethal mechanism involved respiratory compromise from the weight of abdominal viscera on the diaphragm, as well as upper airway compromise due to kinking of the neck and wedging of the head.

The 'canine rescue' phenomenon.

While deaths caused by interactions with dogs in medico-legal situations most often involve trauma from attacks, in certain circumstances, deaths may occur from sharing environmental hazards that the animal has been exposed to during attempted rescues. Search of the Forensic Science South Australia (FSSA), Australia, autopsy database over a 16-year period from 2004 to 2020 found three such cases, including two women aged 46 and 61 years who were both killed in separate incidents after being struck by vehicles when they attempted to rescue dogs that had strayed onto busy roads. The final case was a 53-year-old man who drowned in a river while trying to rescue his dog. A review of Internet databases and news sources revealed other cases where would-be dog rescuers had drowned in rivers and the sea or had succumbed to hypothermia in frozen lakes and waterways. Other hazardous situations involve house fires, falls from heights, electrocution and envenomation. The characteristic features of these cases are of a dog (often a pet) getting itself into, or being found in, a dangerous situation, with owners or bystanders then attempting rescue. The dangers of the situation are either ignored or underestimated by the rescuers who often also misjudge the capacity of dogs to survive/self-rescue. Cases may therefore be encountered in forensic investigations where death or serious injury has occurred during attempts to protect an animal from particular types of environmental dangers. Unlike the owners, it is not infrequently documented that the dogs have survived the danger unharmed.

Crush asphyxia and ride-on lawn mowers.

Search of files at Forensic Science SA, Australia, over the past 20 years (1997-2016) revealed three cases of death due to crush asphyxia associated with the use of ride-on lawn mowers. (1) A 61-year-old man was trapped under a ride-on mower that had rolled over. Autopsy examination revealed congestion and petechial haemorrhages of the face and chest, and markings on the chest associated with underlying rib fractures. (2) A 78-year-old man was trapped under a ride-on mower that had also rolled over. Autopsy examination revealed petechial haemorrhages of the face and chest and markings on the chest. (3) A 72-year-old man was found wedged between a ride-on mower and a tree, with petechial haemorrhages of the face and chest, and markings on the front and back of the chest. These cases demonstrate a rare cause of crush asphyxia, often in older males in the domestic environment, which may arise from more than one mechanism.

Vascular lesions simulating bruising.

Careful examination of the skin and soft tissues is a routine part of the forensic autopsy to identify and characterise traumatic lesions. Three cases are reported where benign vascular lesions presented as bruises. In case 1, a 44-year-old man with a history of epilepsy was found dead on the floor. Dissection of the neck revealed a haemorrhagic area 15 mm × 1.5 mm, deep to the left thyrohyoid muscle. In case 2, an 87-year-old man was found dead with a plastic bag over his head attached to an opened cylinder of nitrogen gas. On the mucosal surface of his upper lip, there was an apparent 5 mm blue/purple bruise. In case 3, examination of the back of a 16-month-old girl revealed an apparent 15 mm bruise. Histological examination of all three lesions revealed benign vascular lesions. In the absence of microscopy, these lesions would have been considered traumatic in origin, raising the possibility of inflicted trauma.

Follow-up calls to next of kin relating to coronial autopsies.

It might be expected that follow-up telephone communication with next of kin relating to coronial autopsies would be distressing, particularly when made months or even years after the death. However, our experience has indicated that this is not the case in the majority of calls.