A man found guilty of the bashing murder of a man almost three years ago has been jailed for at least 20 years in what an Adelaide court described as a "brutal" and "savage" attack.

Key points: Mark Boyce was murdered outside his Elizabeth South home in January 2017

Mark Boyce was murdered outside his Elizabeth South home in January 2017 His murderer, Joshua Roy Grant, has been jailed for at least 20 years

His murderer, Joshua Roy Grant, has been jailed for at least 20 years The sentencing judge described the bashing murder as brutal and savage

Supreme Court Justice Tim Stanley sentenced Joshua Roy Grant, 27, to life imprisonment with a non-parole period of 20 years for the murder of Mark Boyce.

The 36-year-old victim suffered a fatal brain injury when he was beaten by three men — one of which was Grant — outside his home on Hill Street at Elizabeth South, in Adelaide's northern suburbs.

A Supreme Court jury found Grant guilty of murder.

Justice Stanley accepted that Grant did not intend to kill Mr Boyce but was part of a "joint enterprise" to inflict grievous bodily harm.

"The attack on Mark Boyce was savage, brutal and completely unjustified," he said.

"The utter pointlessness of his death can only accentuate the grief of those who knew him and loved him.

"Your counsel, Ms [Marie] Shaw QC, submits that the attack on Mr Boyce was conceived on a spur of the moment — I accept that submission, but that only goes so far.

"While the attack on Mr Boyce was conceived on the spur of the moment, it occurred in the context where you had gone to Hill Street in company with [two others] with the intention of accosting and assaulting [another man]."

Justice Stanley said the fact that they attacked Mr Boyce instead did not make the pre-planning irrelevant.

Judge accepted Grant did not inflict the fatal blow

Justice Stanley said Grant played a lesser role in the bashing by holding down Mr Boyce, but that left him vulnerable to the lethal beating by the two other men.

"I accept that you did not inflict the fatal blow or blows," he said.

"Mark Boyce was a much loved individual. His murder has caused them the most intense grief and anguish — their loss is forever."

He said this was not Grant's first offence for violent crime.

Justice Stanley said he fixed the mandatory minimum non-parole period because the offence was at the "lower end of the scale of objective seriousness" given he did not intend to kill Mr Boyce.

Outside court, Mr Boyce's devastated father Malcolm Boyce said no sentence would bring his son back.

"He was such a character," he said.