Jozef Stefaniak, 24, was killed when Angela Lea Smith, 34, rolled and crashed a car on Yarra Glen in Hughes on January 2.

Smith, and her then boyfriend, who was a good friend of Jozef's, fled the scene.

Jozef's father, Bill Stefaniak - a long-time Canberra politician and former leader of the Canberra Liberals - and his brother John Lane both spoke at an emotional sentence hearing in the ACT Supreme Court.

Bill Stefaniak said his son died because of the criminal behaviour of a so-called friend who bolted from the scene and left him dead and alone on Yarra Glen.

He said Smith tried to blame Jozef for the crash, and allowed her then boyfriend to be charged with the crash.

He said his son's death had been made worse for the family because Smith had shown no remorse or contrition and made no apology to them.

"Had she shown remorse, empathy, stayed at the scene and showed even a modicum of normal human concern and contrition for her actions, I would not be overly concerned with the sentence part [of his statement]," he said.

"But in all the circumstances of this case, I regard her attitude and actions as reprehensible, her manner of driving dangerous in the extreme."

He said he found her lack of regard of the rules of the road and laws of the territory, given she had never held a licence, extremely concerning.

He felt a weak sentence would make a mockery of Jozef's death and the circumstances of it.

Jozef loved dogs, horses and animals in general, Mr Stefaniak told the court. He was supposed to start work at the National Zoo and Aquarium the day after he died.

One week after he died, a mate turned up looking for him to say they had a job on the Great Barrier Reef doing underwater photography.

Mr Stefaniak said he and his wife Shirley would miss Jozef helping them around the home or at work, his computer skills, and making Shirley laugh with his quirky sense of humour.

"Whatever sentence your Honour imposes on the prisoner, she will one day be released and be able to return to whoever in her family wants her," he said.

"Her actions, in effect, sentenced my son to death. He can never come home."

Smith, who is in custody, cried and wiped at her tears while Mr Stefaniak addressed the court.

Mr Lane remembered his brother's great passion for scuba diving, and the child escape artist who once led a great escape of toddlers from the child care centre after opening a locked gate.

He said the centre had to install a new "Joe-proof lock".

It was Mr Lane who took the call from police that Jozef had died, and who had to tell their parents.

Mr Lane said the pain of sharing that news with his parents would stay with him forever.

Smith has pleaded guilty to charges of culpable driving causing death, drug driving, not wearing a seatbelt, and failing to give assistance after a crash.

The case returns to court on February 22.