The 19-year-old who struck and killed South Australian Police Commissioner Grant Steven's son at Schoolies celebrations last year has been handed a suspended sentence.

District Court Judge Joanne Tracey ordered Dhirren Randhawa's sentence of one year, one month and seven days, along with a non-parole period of seven months, be suspended on the condition he be of good behaviour for two years.

Charlie Stevens sustained multiple injuries, including an irreversible brain injury, when Randhawa hit him with his car at Goolwa, south of Adelaide, during Schoolies celebrations on November 17 last year.

Charlie was immediately conveyed to the Flinders Medical Centre where he died on November 18.

Randhawa pleaded guilty to aggravated driving without due care and leaving the scene of a crash at an earlier hearing.

The more serious charge of causing death by dangerous driving and a charge of failing to truly answer questions were dropped.

On Tuesday, Judge Tracey said a sentence imposed by her will never amount to the "tragic loss of life" and grief suffered by the Stevens family.

"In considering the circumstances of the offences, I do not overlook the terrible loss that has been suffered," she said.

"Charlie Stevens was only 18 and a bright future was ahead of him.

"He was much loved and his family are, and will forever remain, grief stricken.

"Nothing said or done here today will heal their pain."

Judge Tracey, in describing the events of November 17, 2023, said Charlie and three of his friends asked Randhawa for a lift on Beach Road but had "an amicable" conversation and declined.

Randhawa drove off, before turning back towards Victor Harbor, when he hit Charlie in the southbound lane.

Judge Tracey said it is accepted Randhawa was accelerating at the time but he was not found to be driving over the speed limit.

"You were accelerating as you approached — the young men moved west towards the verge and you moved across into the southbound lane to allow a safe distance to pass," she said.

Judge Tracey said Randhawa failed to identify Charlie on the eastern side of Beach Road but that when he finally did, he tried to avoid hitting him.

"When you first saw him, you did not immediately brake or accelerate, but turned in a north-westerly direction away from him to avoid hitting him but you were unsuccessful," she said.

Judge Tracey said a psychological report of Randhawa, prepared by forensic psychologist Luke Broomhall, said the 19-year-old's failure to stop can be attributed to a previous traumatic event in 2021 when he was attacked by a group of men.

"You told Mr Broomhall that when you struck Charlie, with the right side of your car, you had slowed but heard yelling behind you and you were instantly scared about the reaction of the group," she said.

"You say you believe that the group was a danger to you and your girlfriend's safety and that you decided not to stop."

Randhawa 'likely panicked' 

Judge Tracey said Randhawa continued to drive along Beach Road before pulling off into a side street and calling his mother who informed him to ring the police.

"Immediately upon speaking to the officers, you identified yourself and volunteered that you had hit someone with your vehicle," she said.

Judge Tracey said Randhawa accepts there is "more [he] could've done to avoid this tragic outcome" and that he had "no intention to harm anyone that night".

"You did not fail to stop … because of some fear that you would be found to have consumed alcohol or drugs," she said.

"However, you realised your vehicle had struck someone and you were required to stop — both morally and legally.

"I accept that at the time you likely panicked and were overwhelmed when you made the very foolish decision to keep driving."

Judge Tracey said since the incident Randhawa has exhibited symptoms of trauma and that he meets the diagnostic criteria for an adjustment disorder.

She said Director of Public Prosecutions Martin Hinton KC and Jane Abbey KC, for Randhawa, both accept that his prospects for rehabilitation are "undoubtedly very good" and that his "remorse is undoubtedly genuine".

"It is accepted that you ought to have paid better attention to any risk that might've presented itself on the other side of the road," she said.

"[I hope] the circumstances here give all road users an opportunity to reflect on the devastating consequences that flow from driving without proper care and serve as a powerful reminder to all drivers of the onerous responsibility that we have as road users.

"The sentence that I impose must bring home to offenders what the community and the law expect."

Judge Tracey said she "does not doubt" that the grief caused to Charlie's friends and family weighs heavily on Randhawa.

"Your pleas of guilty have spared those who were there that night reliving the horror of what they witnessed," she said.

'Difficult, stressful and emotional for our family'

Commissioner Stevens and his family addressed the media outside of court following the sentencing, and said they were grateful that this part of the process was over.

"Each court date that's come up has been difficult, stressful and emotional for our family," Commissioner Stevens said.

"We're grateful that Dhirren chose to plead guilty to this offence because that brought this part of it to a conclusion much more quickly.

"It's not getting any easier, as I'm sure people who have lost a child would appreciate."

Randhawa will not be allowed to hold a driver's licence until at least 2034.