Corey James Martin, 39, smiled and shrugged after he was sentenced by Acting Justice John Nield on Wednesday for the murder of Andre Le Dinh in May 2010.

Mr Le Dinh, 26, died of head injuries after Martin beat him during a drug robbery at the victim's Belconnen unit on May 10.

Martin, also known as Budgie, briefly went to his daughter-in-law's apartment across the hall from Mr Le Dinh's unit before knocking on the victim's door.

Martin then bashed the diminutive Mr Le Dinh - who weighed only 48 kilograms and stood at 165 centimetres - unconscious, stole drugs and money hidden throughout the apartment, and left him choking on his own blood.

He grabbed Mr Le Dinh's head in his ''oafish'' hands and smashed it against the floor, causing two fractures at the back of his skull.

Neighbours reported hearing a sound likened to a bowling ball being dropped on the floor around the time of the incident.

Martin - who weighs 110 kilograms and is 189 centimetres - pleaded not guilty, claiming the pair got into a fight after the smaller man became aggressive during a disagreement over drugs.

He said Mr Le Dinh was standing and conscious when he left the unit.

But a jury found him guilty in May this year of murder.

In handing down sentence on Wednesday, Justice Nield described the attack as vicious, callous, and brutal. ''This was a premeditated, vicious attack of extreme violence on the victim in his own home,'' Justice Nield said.

But he said it was not the worst type of murder.

Justice Nield jailed Martin for 22½ years, backdated to take into account time spent in custody, with a non-parole period of 17 years and six months. He will be eligible for release in 2029.

Family members of Mr Le Dinh cheered and clapped as the judge handed down the sentence.

The court heard the case against Martin was overwhelming, and Justice Nield said the guilty verdict did not surprise him.

He described Martin's case, in which he claimed he was defending himself from the much smaller man, as ''fanciful''.

Police listening devices captured him trying to work out a fake story to explain his purchase of a new car, which he bought using stolen money.

He was also heard telling his partner that he had ''washed his clothes four times''.

Martin, the court heard, also bragged about the death.

''If I wouldn't have kicked him [Mr Le Dinh] in the head one too many times, maybe he'd still be alive today,'' he said to friends.

As the sentence was read out, Martin's supporters told the victim's family to ''shut your f---ing face'' when they clapped in celebration.

Justice Nield spoke of the considerable impact on Mr Le Dinh's family, noting they had spoken eloquently of the loss and emptiness they felt after the murder.

''It is said that a parent should never have to bury a child,'' he said.

''Unfortunately Mr Michael Le Dinh and his wife have had to bury their eldest child.''

Martin, the court heard, had been abused sexually, physically and emotionally as a child by his step father.

Justice Nield said there was a ''real risk'' Martin would reoffend, but said his age upon release from jail may prevent him.

''I suspect his future will be much like his past,'' he said.

Martin was given a 10 per cent discount to his sentence due to new laws recently introduced by the ACT government designed to reward offenders who made admissions that helped speed up the trial.

He had only been out of jail for a month when he murdered Mr Le Dinh.

Two others, who cannot be named, have pleaded guilty to conspiring to rob Mr Le Dinh.