But Coroner Peter Dingwall has urged authorities to learn lessons from what was one of the ACT's most horrific crashes, calling for the mandatory installation of immobilisers in all cars targeted by thieves.

Late one Saturday night in March 2010, Justin Karl Williams was driving a stolen Mazda 626, drunk, unlicensed and with his teenager female passenger, Skye Marree Webbe.

His car was being pursued on Canberra Avenue by NSW Police officers who did not know who was in the car, or why it was fleeing from them.

He ran three red lights and reached speeds of up to 157km/h.

Williams sped through a red light near the Monaro Highway intersection, still being pursued by the police.

One of the officers had decided to end the chase, but was still just behind the car when it ran the light.

Williams ploughed straight into a Mazda turning right, splitting the other car into two.

Inside the car were Scott Raymond Oppelaar, his de facto wife Samantha Leanne Ford, and their baby son Brody Oppelaar.

All three were killed instantly

Williams and his passenger were pulled from the wreckage of the stolen car, and taken to hospital in a desperate attempt to save their lives.

Williams died, but Ms Webbe survived with severe injuries.

It later emerged the two families had known each other.

Williams was already on bail conditions that prevented him from being in the driver's seat of a car, and had bragged on a Facebook group called "F—k the Australian Federal Police" that police could not catch him while he was driving.

The crash sparked a major debate about police pursuits, and particularly about whether officers properly handled the cross-border pursuit, including their failure to communicate and obtain proper permission from ACT police to continue the chase in the territory.

Mr Dingwall, who reserved his findings following an inquest hearing in March 2011, found no criticism could be made of the NSW officers.

He said he was satisfied the pursuit should not have been ended at any time earlier than when one of the officers decided to pull out just before the crash.

"They were carrying out their duty to investigate and apprehend offenders and cannot be criticised for carrying out that duty where a person who had committed an offence in their presence, decided to further disobey the law by refusing to stop when required to do so by them," he wrote.

"It is extremely sad and tragic that four deaths, particularly that of a baby who had not yet experienced much of life, resulted from the unlawful, reckless and selfish behaviour of a person who placed his desire to evade the police, and his ego, ahead of the lives of other road users."

Mr Dingwall called for consideration to be given to the mandatory installation of immobilisers or similar devices in cars that were likely to be the targets of theft.

He said he realised that would face a "great many hurdles" but said it would reduce a great many more deaths involving stolen cars, particularly during police pursuits.

The coroner also recommended training be prepared for ACT and NSW officers, who hold status as special members of the AFP, about cross-border pursuits.

But Mr Dingwall said he was confident that had already taken place by now "in light of the very professional approach of the Australian Federal Police to the investigation".

A spokeswoman for ACT Policing welcomed the findings, confirming the recommendations for further training packages for officers had already been implemented.

''Both training packages are mandatory for any member from either jurisdiction and forms part of their swearing in processes,'' the spokeswoman said.

Mr Dingwall also offered his condolences and sympathy to all families and friends of the four deceased.