Tim Smith-Brown, 24, was driving an unregistered car unlicensed, on bail, and fleeing police when he died in the smash on Drakeford Drive on Friday evening.

The Oxley man's pregnant girlfriend, Felicity Jessop, and three others were also injured in the accident.

But Smith-Brown's mother – who said he would have been "shattered" to know he had hurt others – claimed her son had been unfairly attacked in the public backlash in the aftermath of the fatal accident.

A police statement, issued on Saturday morning, said officers had attempted to pull over a vehicle of interest about 5.45pm on Friday.

The driver of the car accelerated away from police who "followed for a short time until the response was terminated".

Soon after, Smith-Brown allegedly ran a red light and hit two other cars.

Felicity Jessop was rushed to hospital and gave birth to a boy, who she named Tim after his father.

A man, 66, and woman, 64, remained in a stable condition in hospital on Monday. A girl, 16, has since been discharged.

Earlier this year, Smith-Brown pleaded guilty in the ACT Magistrates Court to a charge of furious driving and obstructing police.

He had not entered pleas to two charges of driving while disqualified from the same incident in November last year.

Court documents said police stopped Smith-Brown's white ute in Oxley on the afternoon of November 27 after checks revealed he had a suspended licence.

Ms Jessop was in the passenger seat when police approached the car and asked Smith-Brown to turn off the engine.

But he instead accelerated away, forcing an officer to jump away from his car to avoid being hit, and almost collided with the police vehicle as he escaped.

Police did not attempt to pursue the vehicle, and instead negotiated his surrender.

Smith-Brown handed himself into police more than two weeks later, and, during an interview, said he had fled out of panic.

His mother Joanne Smith, also of Oxley, said her son was "a loveable rogue".

"He wanted to help everyone, he'd be mortified to know he hurt that elderly couple, he'd be so shattered.

"He was so looking forward to being a dad and we were talking about all the different things he was going to do."

Ms Smith said members of the public had painted a "horrible picture" of her son through heated discussions on social media.

"All it was was his car was unregistered and now he's dead.

"It's just so sad, so very, very sad. I don't know what he was thinking."

Baby Tim remained in hospital with Ms Jessop, who was to undergo further surgery on Monday. Ms Smith said the new mother was "lost".

"She remembers everything up until the point of impact. This was something they were going to do together."

Smith-Brown's father Warren Brown said his son's actions were "silly" and he wouldn't make excuses for him.

"He was doing the wrong thing, I know he was doing the wrong thing. But try to pretend he was your child is what I'm saying.

"Your child's your child."

Mr Brown described his son as his "best mate", a loyal friend and said "at least 60 per cent of Tuggeranong knew him".

Smith-Brown went to St Anthony's Primary School in Wanniassa, Erindale College and Calwell High School.

He'd had numerous jobs since he left school but wasn't working at the time of his death.

"He was the life of every party," Mr Brown said. "He was very cheeky, and very loving."

"He was just your typical bloke who got caught up in the wrong stuff and he was trying awfully hard to get out of it."

Mr Brown said he didn't know the full details of the crash but he understood his son and Ms Jessop were on their way to Tuggeranong and his son was driving an unregistered car without a licence.

"He was very loved by very many people. Unfortunately he made a wrong decision and he paid with his life."

Police said they tried to pull over the "vehicle of interest" about 5.45pm before the driver allegedly sped away from them, prompting short pursuit.

They ended their chase some time before the crash, but the car continued at high speeds along Drakeford Drive, running the red light at the intersection with Marconi Crescent and Boddington Crescent, near the Kambah shops.

Police have declined to comment on what time the chase was called off or the reason it was terminated and said that information would be part of the investigation.

ACT Policing have started two internal inquiries into the crash and the matter will be referred to the Coroner.

Police chief satisfied officers 'exactly followed' pursuit guidelines

ACT chief police officer Rudi Lammers on Tuesday defended the actions of the officers involved and said police pursuits were "very heavily regulated" and territory police followed stringent guidelines.

"I've had the opportunity over the last three days to examine the evidence in relation to this collision and at this point in time, and not withstanding what the coroner is likely to say, I'm satisfied that the officers who were pursuing the vehicle followed exactly our guidelines, our protocols and our procedures."

Police Minister Joy Burch said ACT Policing had "very clear policies and frameworks" around their activities.

"On the matter of police pursuits it is a very fine balance allowing police to do the duties to keep our community safe.

"But the public risk for drivers to don't pull over, who run a red light, unfortunately the consequences here were tragic."

Australian Federal Police Association president Dennis Gellatly said officers were required to make split-second decisions for pursuits that took into account a wide range of factors including the surrounding environment, traffic conditions, and the number of people in the car.

He said any time a chase was initiated a pursuit controller, or senior officer in police operations, was brought in to oversee the incident. The controller, and the officers involved, could halt the chase at any point and for any reason.

"The guideline's very stringent and tries to balance the need for police to exercise their judgement and discretion with the risks that are apparent."

Mr Gellatly said the officers involved had been offered counselling and support from staff, including Assistant Commissioner Lammers.

"It does weigh heavily, it's not something you would want to come home from a shift having gone through."

Greens Minister Shane Rattenbury, who previously called for an inquiry into more restrictive policies for police chases in the ACT, said any pursuit regulations needed to strike a balance between law enforcement and community safety.

"I fall on the side of saying the risk is not worth it," he said.

Mr Rattenbury said traffic offences sparked the majority of police pursuits and he believed only drivers who had committed a serious offence should be pursued.

"We've seen the terrible consequences of what can go wrong with a police pursuit, and that sends ripples through the community."