Unusual motor vehicle suicides

Journal of Clinical Forensic Medicine (2001) 8, 1±4 ß APS/Harcourt Publishers Ltd 2001 doi: 10.1054/jcfm.2000.0457, available online at http://www.idealibrary.com on

ORIGINAL COMMUNICATION

Unusual motor vehicle suicides R. W. Byard, R. A. James Forensic Science Centre, Adelaide, Australia SUMMARY. A review was undertaken of cases in which motor vehicles were used to commit suicide. While the most common methods involved carbon monoxide toxicity or the sustaining of multiple injuries, three unusual cases were found involving: (i) hanging from a car seat belt, (ii) self immolation inside a car, and (iii) setting up a crash situation. The latter two cases were used as a backup to drug overdose. Problems that may occur in determining the manner of death are described. ß APS/Harcourt Publishers Ltd 2001 Journal of Clinical Forensic Medicine (2001) 8, 1±4 INTRODUCTION

(5) vehicle ¯ammability to assist self immolation; (6) vehicle ®xtures (e.g. seatbelt) or ropes for hanging or ligature strangulation; and (7) the vehicle to set up a crash situation as a backup to suicide by other means.

Motor vehicles have provided unique opportunities for self destruction. The following series of cases are presented to give details of three unusual suicides involving motor vehicles, as well as providing an overview of other types of suicides that may occur.

CASE REPORTS Case 1

MATERIALS AND METHODS

A 47-year-old male was found sitting in the front seat of his truck with the seat belt harness wrapped tightly around his neck. The belt was looped over, with the right hand holding the loop tight. The deceased had recently been expressing suicidal ideation. At autopsy the only signi®cant ®ndings were of a ligature impression with a weave pattern extending around the neck, with the point of suspension above and to the left of the thyroid cartilage (Figs 1A & B). Numerous petechial haemorrhages were present over the eyelids. Death was due to low suspension hanging from the truck seat belt.

Review of pathology ®les at the Forensic Science Centre over a 20-year period from July 1980 to June 2000 was undertaken for cases of suicide where a motor vehicle formed an integral part of the process. RESULTS Cases fell into seven categories where the deceased individuals had used: (1) vehicle exhaust to cause fatal carbon-monoxide toxicity; (2) the speed and mass of their own vehicle to in¯ict lethal injuries, e.g. driving a vehicle into a stationary object at speed, or driving over a cliff; (3) the speed and mass of another vehicle to sustain lethal injuries, e.g. stepping in front of a large vehicle moving at speed, stopping a car on train tracks; (4) the weight of a vehicle to assist drowning;

Case 2 A 48-year-old male was found incinerated in a car on his property. He had informed his wife one evening that he was going out, and had then doused himself and the car interior with petrol. He had also wired his left wrist to the steering wheel (Fig. 2), presumably to prevent inadvertent escape during the ®re. He had then set himself and the car on ®re while sitting inside. At autopsy the body was markedly charred with soot in the trachea. There was no gastric aspiration. The

Assoc Professor Roger W. Byard, R. A. James, Forensic Science Centre, 21 Divett Place, Adelaide 5000, Australia Correspondence to: R. W. Byard, Tel.: ‡61 8 8226 7700; Fax: ‡61 8 8226 7777; E-mail: [email protected] 1

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Fig. 1 (A) Looping of the seat belt around the neck in Case 1 with holding of the loop in the right hand to facilitate hanging. (B) Ligature mark under the neck in Case 1.

blood carboxyhaemoglobin level of 20% was elevated but not lethal, indicating that the deceased had been alive at the time of the ®re. There was also a toxic level of oxazepam (4.9 mg/L). Death was due to incineration.

Case 3 A 51-year-old physician was found dead in his car following a collision in a car park with a stationary car and a fence. Witnesses had heard a loud car engine noise for some time prior to the impact. At the scene a scalp vein needle was noted to be inserted into the dorsum of the right hand and a piece of broken broom handle was found wedged against the accelerator depressing it fully. At autopsy the only evidence of trauma was a small abrasion over the left eyebrow and a small abrasion in the mid-chest region. An

intravenous puncture wound was present in the dorsum of his hand as noted. There were no skull fractures, brain or internal organ injuries, or underlying illnesses which could have caused or contributed to death. Toxicological evaluation of blood revealed a sublethal thiopentone level of 7 mg/L. Given that the thiopentone level was not fatal, it appears that the most likely cause of death was commotio cordis associated with the mid-chest abrasion from impact with the car steering wheel. The thiopentone would have caused the deceased to fall unconscious, thus releasing the pressure of his foot on the clutch of the car, and resulting in acceleration toward the fence. No signi®cance psychiatric histories were found and all were classi®ed as suicides only after full forensic autopsies and police investigations had been conducted. There were no suspicious circumstances or unexplained physical injuries or ®ndings at autopsy in any of the cases.

DISCUSSION

Fig. 2 Wire tied around the wrist and steering wheel by the deceased in Case 2 to prevent escape from a burning car.

Suicide is now the leading cause of violent death in Australia, with more deaths attributed to acts of deliberate self destruction than to either homicides or to motor vehicle accidents.1,2 Favoured methods of suicide include hanging, carbon-monoxide inhalation, gunshots and drug overdoses, which account for more than 90% of cases.2 Methods of suicide have been shown to vary at different ages, with accessibility to devices and comprehension of lethal outcomes being signi®cant factors in determining choice.3 Asphyxia from seatbelts is an extremely uncommon event, most often occurring after a vehicle accident in an individual who is in some way impaired, thus

Unusual motor vehicle suicides 3 preventing escape from the harness. Incapacitation may be due to unconsciousness or paralysis.4Although hanging inside a car from a rope,5 and strangulation from ligatures tied around the neck to stationary objects6,7 have been reported, we are not aware of other cases where suicide has occurred using a vehicle seatbelt (as in Case 1). The con®ned nature of vehicle cabins presumably makes hanging under these circumstances technically dif®cult. Deaths due to vehicle ®res usually involve individuals who have been trapped in a burning vehicle after an accident or children who have set ®re to a car accidentally and have not been able to escape.8,9 An attempt to conceal a homicide must also be considered. However, at the autopsy of a badly charred body there are usually no features to help to distinguish suicide from an accident or homicide. Radiography will help to exclude gunshot wounds. Suicides due to self-immolation are uncommon in Western communities, and those involving vehicles are extremely rare, although the interiors of modern cars are highly ¯ammable and rapidly generate considerable heat.9 In Case 2 the suicide by selfimmolation was backed up by the ingestion of oxazepam. Case 3 represents another unusual situation where a car was used as a `failsafe' device to back up the effect of a drug. The deceased had apparently depressed the car clutch with his foot and then wedged the accelerator to the ¯oor so that the clutch would engage once the injected barbiturate had caused him to collapse. The intention appears to have been to cause lethal injury by crashing the car. Carbon-monoxide toxicity accounted for the majority of cases of vehicle suicides. The usual method involved running a hose pipe from the exhaust to the vehicle cabin. Alternatively, the deceased may have left the car running in an enclosed space such as a garage. Although the circumstances of these deaths strongly suggested suicide, autopsy examinations were often complicated by marked putrefaction of the bodies. There were several reasons for this, including the relatively high temperature of the cabin at the time of death due to heating by engine emissions and the often isolated site chosen for the suicide, resulting in delay before the body was found. In addition, the internal temperatures of cars exposed to direct sunlight may reach extremely high levels with only moderate ambient temperatures.10 While the keystone to diagnosis is the demonstration of lethal levels of carbon monoxide, mummi®cation or skeletonization of bodies that were not found for some time on occasion precluded the assessment of carbon monoxide in body ¯uids. In these cases a disguised homicide may again be dif®cult to exclude.

Problems also occurred in determining whether a single vehicle collision was due to an accident or to suicide. The decision was less complicated if typical characteristics of suicide in a depressed individual were present, such as a note, previous suicide attempts and a history of suicidal ideation. However, often none of these features were found. Investigation by special police units was then vital to provide an analysis of road and weather conditions, vehicle function and speed, and presence or absence of skid marks or attempts to avoid impact.11 Blood alcohol and drug screens are mandatory at autopsy, in addition to searching for underlying organic disease, to assist in the assessment of driving competence at the time of the impact. Similarly, on occasion it was dif®cult to distinguish a simple pedestrian-vehicle accident from a suicide, as the autopsy examination was only able to determine the array of injuries present, and possibly the sites of primary and secondary impact. However, in certain cases, reliable witnesses, other than the driver, may have observed the deceased stepping in front of, or turning to face, the vehicle. In at least one case there were also earlier `hesitation episodes' witnessed, where the deceased had stepped in front of other vehicles but had stepped back prior to impact. Suicide in which an individual used a car as a weight and/or restraint to ensure drowning is rare in our experience. These cases require access to relatively deep water, preferably in an area where rescue is unlikely. Most cases in South Australia have involved cars being driven off mooring jetties, either on beaches, or along large inland rivers. On occasion cars have been driven off cliff edges presumably to ensure that drowning will be a backup in cases where injuries sustained in the fall were not lethal. In conclusion, motor vehicles have become important instruments of self-destruction. Accessibility to motor vehicles, with the opportunity to drive the vehicle to an isolated area to provide suf®cient time for death, are factors which lead to their continued use in suicide attempts. The non-violent mechanism of death with exhaust inhalation is also an aspect which may appeal to certain individuals. On the other hand, the almost certain and probably rapidly fatal outcome of a high-speed collision, or standing in front of a large vehicle such as a truck, has been of greater signi®cance to other individuals. The absence of apparatus in the form of a hose pipe and tape that are required for carbon-monoxide deaths also means that suicides relying on massive injuries from vehicle trauma may be undertaken with less planning. Other forms of suicide involving vehicles such as hanging and selfimmolation remain distinctly uncommon and require careful investigation to exclude homicide.

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ACKNOWLEDGEMENTS We would like to thank the South Australian State Coroner, Mr Wayne Chivell, for permission to publish details of these cases. REFERENCES 1. Causes of Death, Australia 1995. Catalogue No. 3303.0. Australian Bureau of Statistics: Australian Government Publishing Service, 1996 2. Baume P, Mctaggart P. Suicides in Australia. In: Kosky RJ, Eshkavari HS, Goldney RD, Hassan R (eds) Suicide Prevention. The Global Context. New York: Plenum Press, 1998; 67±78 3. Byard RW, Markopoulos D, Prasad D, Eitzen D, James RA, Blackbourne B, Krous HF. Early adolescent suicide ± a comparative study. J Clin Forensic Med 2000; 7: 6±9 4. James RA, Byard RW. Asphyxiation from shoulder seat belts ± an unusual motor vehicle injury. Am J Forensic Med Pathol (In press)

5. Durso S, Del Vecchio S, Ciallela C. Hanging in an automobile: a report on a unique case history. Am J Forensic Med Pathol 1995; 16: 352±354 6. Hardwicke MB, Taff ML, Spitz WU. A case of suicidal hanging in an automobile. Am J Forensic Med Pathol 1985; 6: 362±364 7. Marshall TK. Suicidal hanging in an automobile (letter) Am J Forensic Med Pathol 1987; 8: 89±90 8. Knight B. Transportation injuries. In. Forensic Pathology, 2nd edn. London Arnold, 1997; p. 283 9. Byard RW, Lipsett J, Gilbert J. Fire deaths in children in South Australia from 1989 to 1998. J Paediatr Child Health 2000; 36: 176±178 10. Byard RW, Bourne AJ, James RA. Childhood deaths and cargo barriers in cars. J Paediatr Child Health 1999; 35: 409±410 11. Imajo T. Suicide by motor vehicle. J Forensic Sci 1983; 28: 83±89