We asked John to contribute reminiscences about his experiences.

BACK when I was a street-level detective, from the 1960s through to the 1980s, detectives generally didn't become involved in motor vehicle accident investigations unless somebody was killed or seriously injured.

In those circumstances we would approach it like any other criminal investigation - to establish whether a criminal offence had been committed, such as culpable driving or manslaughter.

Many serious accidents had tragic consequences, such as a passenger, or an occupant of another car, being killed or seriously injured through no fault of their own - just in the wrong place at the wrong time. One in particular stands out in my memory.

Just before midnight on Friday, December 28, 1979, while working the Newcastle wireless car, my partner Bob Guyatt and I were called to the Pacific Highway south of Swansea, about one kilometre north of the Frazer Park turnoff.

We were met with the sight of a Datsun sedan lodged against the guardrail on the western side of the road, facing north. The car had been gutted by fire and there was the form of a human body, burnt beyond recognition, in the front passenger seat.

The car's petrol tank was lying on the roadway, the nearside (passenger side) rear door had been ripped apart and the nearside rear mudguard was ripped open. We were told that the driver of the Datsun had been taken by ambulance to Belmont Hospital with serious burns to the arms, head, chest and elsewhere.

Close by was a Holden utility, also fire-damaged, with its windscreen shattered and its interior gutted by fire. The driver had died from his burns and an incinerated dog was still on the floor.

There was damage to the guardrail about 40 metres back from the Datsun and fresh marks on the roadway. At this point the roadway had four lanes, two lanes each way, however for traffic travelling north it had only widened from one lane to two a few hundred metres beforehand.

Witnesses in following vehicles were unable to say definitively how the accident unfolded, however, they all stated that the traffic was travelling under the speed limit and that the Holden utility, leader of that group of vehicles, had remained in the centre lane after the road had widened to two lanes.

I interviewed the driver of the Datsun at Belmont Hospital, a young man, from Sydney, absolutely distraught that his girlfriend had been killed. Although badly burnt himself, he had suffered further as he tried to free her. He told me that he had followed the utility for some distance after the road widened and, when the utility gave no indication of moving over into the slow lane, he started to overtake it on the nearside.

As he did so, the utility veered over towards him, he swerved away, struck the guardrail and lost control of the car, which came to a halt and burst into flames. This was plausible and was not contradicted by any of the following drivers.

He was not speeding and had followed the utility for some distance before beginning to overtake it on the nearside - so I felt I could rule out criminal charges against the young driver. However, it was important to determine exactly what occurred, to assist the coroner in determining the causes of death.

I returned to the scene in daylight and walked the route from the road-widening point to the accident scene; I again examined the Datsun and the Holden utility (in the yard of the Swansea Police Station). Finally I contacted Jim Sullivan, a former race car driver who had motoring shows on NBN - Motorscope and Drive Alive - and sought his expert advice.

Jim visited the scene and inspected the cars and photographs with me and proffered his opinion on precisely how the accident occurred: the Datsun taking evasive action and striking the guard rail, the fuel tank being ripped out on impact and splashing petrol inside that car then being thrown into the air and striking the bonnet, then the windscreen of the utility, again spreading petrol and the fire.

This explanation made perfect sense and I was able to advise the coroner, at the inquest, of how the accident and the resulting deaths occurred, and to confidently assert that the driver of the Datsun did not commit any unlawful act causing the deaths. The coroner's finding echoed that view.

After the inquest the young man's parents and the parents of the young woman who died under these tragic circumstances (a close-knit group), all expressed their gratitude that the young man could hopefully get on with his life without the burden of guilt that he had carried during the intervening months.

A truly tragic accident with tragic effects on three families, as well as those who witnessed the horrific crash. And if Jim Sullivan is still around - thank you again.