A man who "up-ended the world" of the elderly pensioner he attacked with a hammer before stealing his car in a "cowardly and ghastly" attack could be released from prison in less than three years.
Darryl Trevor St Clair had just been released from hospital and was on methamphetamine when he knocked on the door of an Ascot Park property in October 2021 holding a rock.
St Clair asked Warren Phillips, who had lived in the house for 70 years, to drive him to Marion Road because he was "afraid of people following" him.
Mr Phillips agreed "in an act of good Samaritanism", but St Clair became violent on the drive and threatened Mr Phillips with a hammer.
It caused Mr Phillips to crash into a parked taxi at South Plympton in Adelaide's south.
St Clair then got out of the car and attacked Mr Phillips with the hammer, causing cuts, abrasions and bruising to his hands, face, head and ribs.
St Clair then stole the car keys and drove away.
The 39-year-old was arrested after the media published CCTV footage of the incident and his own uncle recognised him and reported him to police.
He pleaded guilty to aggravated robbery.
District Court Judge Joana Fuller sentenced St Clair to four years and 10 months in jail, saying the crime had "a debilitating effect" on Mr Phillips.
"The footage of your behaviour is disturbing to witness and must have been terrifying to experience," she said during sentencing.
"Your attack on an elderly man trying to help you was cowardly and it was ghastly.
"After throwing him to the ground you left him there and stole one of his most important possessions which, because of you, he has never recovered and he now cannot replace."
Judge Fuller said Mr Phillip's car, which had never been found, was not insured and was Mr Phillip's "key to his independence and ability to move around the community".
She said St Clair's mental state was "disturbed by drug use" at the time, causing him to snap and assault his victim.
"It is clear that when you're using drugs, you are a danger to the community," Judge Fuller said.
"It is a sad indictment on our society that there seems to be no end or limit to the havoc that is wrought by drug use and abuse.
"It's ruined your life and it has up-ended the world of an elderly man."
Judge Fuller said St Clair had committed numerous prior offences, including causing harm by dangerous driving, assault, theft and illegal use and breaches of bail.
"This is by far your most serious offence to date," she said.
The court heard St Clair was released from prison on a public holiday days before the crime and that he had no money or way to get home. It also heard he had suffered an anxiety attack which triggered the drug use.
St Clair will be eligible for parole in just under three years.
Outside court, St Clair's lawyer, Tim McGrath, said he thought the sentence was "fair".
"Unfortunately, the tragedy that was visited upon Mr Phillips is going to go on a lot longer than that sentence.
"He regrets his actions. He's very sorry. He deeply regrets that."
