The mother of a West Australian man who was fatally bashed over the head with a metal pole says she is "trembling" over the disappointing seven-and-a-half-year sentence handed to her son's killer.
A taxi driver found 21-year-old Josh Warneke by the side of a road in Broome on February 26, 2010.
He died from massive head injuries after being struck with a pole from behind by 23-year-old Gene Gibson.
The offender was originally charged with Mr Warneke's murder, but the charge was later downgraded to manslaughter after the police interview was deemed inadmissable because they had not followed proper processes.
Gibson, who is from an Aboriginal community and speaks little English, had an interpreter with him during his sentencing on Wednesday.
Justice Lindy Jenkins said Gibson had a criminal record and a history of petrol sniffing and binge drinking.
She said Gibson's behaviour changed when he was drinking.
"You are capable of getting angry over small things and turning that anger into violence," she said.
Justice Jenkins said Gibson had two years to stop drinking in between committing the crime and police arresting him, but he did not do that.
"My worry is that you don't seem to have the ability to give up," she said.
The court heard Mr Warneke was taken by surprise.
"He had no chance to protect himself from your blow," Justice Jenkins said.
"The blow must have been very hard."
Justice Jenkins said it was a "cowardly act" and the victim had not done anything to provoke such violence, despite Gibson's belief the victim had made a racial slur towards him.
"He was an unarmed stranger," she said.
"He was walking along the road and he posed no threat to you."
Justice Jenkins noted that Gibson was sorry, but said his remorse carried little weight if he was going to continue to drink and be angry.
She also recognised that jail would be hard for Gibson because he would be away from his community, which had already ostracised him due to his crime.
Gibson must serve at least five-and-a-half years in prison before being eligible for parole.
Outside court, Mr Warneke's mother, Ingrid Bishop, told reporters she was shocked and appalled by the sentenced and doubted Gibson could be rehabilitated in prison.
"I don't know if I'm trembling from anger or from shock or from total disbelief," she said.
Ms Bishop also expressed disappointment that she was not allowed to read her victim impact statement in court so that Gibson could know how she felt, due to the potential for "theatrics".
She said she wanted to see reform in the legal system and hoped for an appeal of the sentence.