Cyclist commits suicide by crashing into a wall going full speed

Germany. A 71-year-old man was found lying on the road at a village junction (30 km/h zone) with severe head injuries on a Sunday shortly after midnight. The bicycle he had used still lay between his legs. Resuscitation attempts were unsuccessful, and death was certified still at the scene. As a traffic accident was assumed, the traffic police were called. Further investigations showed that the man had been reported missing by his life partner the day before. She had found a suicide note disclosing the man’s intention to commit suicide for fear of dementia. Thus, the case was taken over by the criminal investigation department.

Trace evidence showed that the cyclist had rolled down a hill road (gradient of 9.5% decreasing to approx. 3% at the final position of the body). At the time of the event, the road surface had been dry and the street lamp lighting the junction had been properly working.

Fig.1 Open craniocerebral trauma. The site of impact in the fronto-parietal region.

On the wall of the building located at the junction, which was covered with the usual roughcast, traces of blood, tissue, and head hair were found at a mean level of 155 cm (5 ft) above the street. Below this impact site, the wall showed scratch marks as well as black rubbed-off particles originating from the front tire of the bike. Between the building’s wall and the final position of the cyclist, fragments of plastic from the bicycle’s damaged front light and further traces of blood were detected.

A second visit paid to the scene in daylight did not reveal any further evidence; in particular, there were no lock-up traces of the brakes and no clues about another vehicle having been involved in the event.

Fig.2 Fragmentation of the bony skullcap.

According to witnesses, the man had used his bike for a long time and was very familiar with the location of the incident. The technical inspection showed that the highest gear had been engaged at the time of the collision. The front fork and the frame tubing below the seat post were kinked backward and twisted. The front-wheel was massively deformed. Its tire and the flat inner tube had come off the broken rim. The back tire was undamaged; its tread did not show any signs of rubber abrasion that would have pointed to a full application of the brake and locking up of the rear wheel. Scratch and impact marks were found on the handlebar and front tire as well as minor traces of blood. Due to the serious damage caused by the crash, the original working condition of the rim brakes could not be assessed.

Fig.3 Scene of the bicycle crash shortly after midnight with the corpse still lying in front of the house. Close-up view of the wall at the impact site.

The male body was autopsied with the following results: Excoriations on both kneecaps with epidermal shreds facing upwards towards the head with a transverse tear-like soft tissue severance. Small superficial excoriations on the extensor side of several finger joints, especially on the left hand. Two adjacent lacerations in the parietal region with irregularly abraded wound edges associated with numerous parallel, finely striped skin excoriations partly resembling superficial furrows, mostly running in an anteroposterior direction. Fragmentation of the cranial and upper facial skull as well as the skull base and local destruction of the adjacent cerebral matter. Two gaping tear wounds of the facial skin without concomitant abrasion. Compression fracture of the 5th thoracic vertebra.

Transmural, semicircular rupture of the aorta at the level of the vertebral fracture. Haemothorax (1200 ml) and compression atelectasis of the left lung. Sparse hypostasis.

Blood alcohol concentration was 0.46 per mille (46 mg per decilitre). Perineum and testicles were unaffected. There were no contusions of the cerebral cortex or signs of blood aspiration. As pre-existing pathologies, general arteriosclerosis, especially in the coronary arteries, and a status following myocardial infarction, bypass surgery, and coronary stent insertion were found. Death was caused by exsanguination due to traumatic transmural rupture of the aorta and open craniocerebral trauma.

Fig.4 The bicycle with deformed and broken front wheel.

In this case, the suicide was confirmed by a hand-written suicide note. To what extent the man’s fear of dementia was justified could not be clarified. Haw et al. emphasized that the risk of suicide in dementia is increased during the diagnostic process and soon after diagnosis. The circumstances at the scene and the results of the technical inspection of the bicycle (e.g. absence of skid marks on the road and of lock-up traces on the tires) provided further supportive evidence of suicide.

The injury pattern suggested that the cyclist had crashed into the wall of the house with the upper part of his body bent forward. This assumption was based on the localization of lacerations in the frontoparietal region with concomitant parallel excoriations – consistent with the plaster of the wall – and the absence of facial excoriations below the eyebrows. The compression fracture of the 5th thoracic vertebra was caused by axial impaction and associated with aortic rupture at the same level. The skin tears on the forehead and at the inner angle of the left eye had no abraded margins and were explained as indirect lesions due to elevated intracranial pressure and skull deformation. The blood ethanol concentration of 0.46 per mille suggested alcohol-related disinhibition (so-called ‘‘courage dose’’).

Suicides in road traffic can be diagnosed only after comprehensive police investigations including medicolegal autopsy and technical assessment. The case presented here is a proven suicide of a bicyclist who intentionally crashed into the wall of a house at the end of a hill road.