Updated 2.55PM: The family of a North Otago man brutally murdered in his own home are thrilled with the sentences received by his killers.

Robert Cummings, Stephen Boskell and Ryan Geary-Smart will spend at least 18 years behind bars for the killing of Justin McFarlane. 

Geary-Smart's brother Jacob has been given a slightly lighter sentence, of 17 years.

Justice Gendall described the killing as unprovoked and vicious, saying Mr McFarlane was in a vulnerable situation when he was attacked by the group.

Mr McFarlane's sister, Kim Julius says the sentence was more than they expected.

"Eighteen years before they're eligible for parole - fantastic," she said.

"We were hoping for seventeen but it's great."

As Justice Gendall handed down his sentence, for one side of the court, there was a feeling of relief, while supporters of the guilty men sobbed.

The Crown has revealed to the High Court that Cummings had only been released from prison a few weeks earlier.

In her submissions, Crown Prosecutor Lisa Preston told the court that the group was involved in a number of violent criminal acts.

"Literally the evening that Robert Cummings returned to Oamaru having been released from prison, this group began asserting their dominance over what they saw as their patch."

The four men had gone to Mr McFarlane's home to buy drugs.

The attack started when Boskell hit him with a beer bottle, then with a fire shovel.

Over the course of the violent assault the Crown told the jury Mr McFarlane was tied up with an electrical cord, stomped on and smacked with a golf club.

Preston said that a starting point of about 17 years is suitable for the men. 

Boskell's lawyer John Westage told Justice Gendall, while he accepts a starting point of around 17 years, this could have a massive effect of his client.

"I accept the family are here and this is a huge tragedy, but you would be sentencing Mr Boskell to a sentence possibly longer than the time he has been on earth."

Westgate said a more appropriate starting point for his 20-year-old client would have been around 14 years.