Steven Churchis was just 17 years-old, living on the streets of Auckland and was full of beer when he attacked a homeless man and left him to die in an alleyway.
Churchis was sentenced at the High Court in Auckland to life in prison with a minimum non-parole period of 11 and-a-half years, today.
The Court heard how Churchis had been drinking in Albert Park with friends on July 30 last year when a fight broke out.
Churchis hurled a half full beer bottle at the boy's head, which knocked him down.
He then threw a flurry of punches which connected with the boy's face.
After running away, a member of the public saw his face covered in blood and called police.
Later in hospital he was found to have a broken nose.
Churchis later told police one of his friends had been paying too much attention to his girlfriend.
Churchis was sentenced to two years and three months jail for that attack today.
On the same day and just hours after the attack, Churchis and his friends were looking for a place to sleep.
They went to Mills Lane, in behind Queen St, where one of the teens had stashed a bag of belongings.
The teenagers came across Edwin Linder defecating.
Mr Linder was 42 and also homeless.
He had been attacked some years before in Sydney and had a brain injury which left him disabled.
Churchis had also had an earlier run in with Mr Linder and later told police Mr Linder had stolen his bag.
The Court heard how Churchis roundhouse kicked Mr Linder in the head before throwing a series of punches.
Churchis' friends who gave evidence at trial said Churchis also stomped on Mr Linder's face.
The boys left but came back and one of Churchis' friends tipped a bottle of urine on Mr Linder's unconscious head.
He was found by people on their way to work the following day and later died in hospital.
Churchis' lawyer Peter Winter said his client had suffered from a flashback before the assault,
today in court.
He said his client had witnessed his mother being beaten by his stepfather and that had affected him.
Crown prosecutor John Dixon said Churchis attacked Mr Linder, despite knowing of the older man's disability.
He also pointed out that even though Churchis returned in the early hours to check on Mr Linder, he never called an ambulance.
Justice Venning described the attack as "savage".
"You launched a martial arts-style kick to his head and then delivered several punches to his head.
"On your own statement, you punched him repeatedly, even after he was on the ground."
Justice Venning said the family of Mr Linder had been haunted by the murder.
He took into account Churchis' young age and an apology letter Churchis wrote to the court and the Linder family when deciding on the sentence, he said.
The judge also encouraged Churchis to get help for his violent behaviour while he was inside prison.