Allan McDevitt, 31, was at twice the legal blood alcohol limit, and driving at almost double the speed limit when he drove a stolen car down the wrong side of the road and hit a parked car in Hadfield last July, the County Koori Court heard on Tuesday.

He was driving at 94 km/h in a 50 km/h zone when he braked, skidding to about 24 km/hour when he struck the car.

His blood alcohol limit was later found to be 0.1 per cent.

Enzo Bassan had just driven his partner, Concetta Guzzo, 74, home when his car was struck, throwing Ms Guzzo 4½f metres onto the concrete driveway.

She was taken to hospital with serious head injuries and died three weeks later.

Prosecutor Stephen Ballek said that McDevitt ran away from the scene, but later returned, telling police "I f---ed up. I did it. Get a knife and stab me in the heart" and was arrested after a scuffle.

The Glenroy man pleaded guilty to stealing a car, culpable driving causing death, and driving without a licence.

He apologised to Ms Guzzo's family members who were sitting in court, saying he hoped they could forgive him in time.

Ms Guzzo's daughter, Patricia Russo, cried as she read her victim impact statement to the court.

She said her mother had been killed just when she had found "peace and happiness in retirement".

She had left her abusive and alcoholic husband and worked hard to raise her four children as a single mother.

"The best years of her life were taken from her. I didn't get the chance to say goodbye and that will haunt me for the rest of my life," she said.

Mr Bassan told the court he cried every day, grieving for his partner of more than 20 years.

Aboriginal elders reprimanded McDevitt for reoffending, after striking and killing a pedestrian while drink-driving in 2007. For that incident he was given a suspended sentence for careless driving.

The court heard that in the earlier incident, McDevitt had driven through water on a road in Coburg, and over-steered, causing his car to rotate and mount a path, striking a 53-year-old pedestrian, who later died at the scene.

Taungurung woman Jacqui Stewart said he had made a "mockery" of the Koori Court.

"You've not only disrespected your community and your family but my family, who I am and what I'm part of and that's the Kulin nation," she said.

Wiradjiri man Steven Delaney said McDevitt had been "selfish" for drinking and driving: "Someone has paid the ultimate price they can never come back."

McDevitt, he said, should have changed his life after the first pedestrian's death: "But you've elected to keep rolling the same way ... the bottom line is you make those choices."

Defence counsel Michael Stanton said his client had been diagnosed with post-traumatic stress disorder after the fatal crash in 2007 and had suffered chronic depression for about a decade.

Arthur McDevitt, told the court that his grandson had no "malice" in him, only "weakness".

While it did not excuse his actions, McDevitt had been racially abused as a young child.

"He didn't believe [he had a] space in society and saw alcohol and drugs as a refuge to allow him to feel, even for a moment, like he belongs."

Judge Paul Grant will sentence him on November 10.