A teenager who bashed an 87-year-old man to death in the victim's Christchurch home has been sentenced to life imprisonment.
Taniela Waitokia, 18, will serve a minimum non-parole period of 11 years and six months for the murder of Harold Richardson in 2015.
Waitokia was 16 and under the influence of drugs when he struck Mr Richardson, a person known to him, at least 14 times with a bottle in what Justice Cameron Mander described as "a sustained and brutal attack".
During sentencing in the High Court at Christchurch on Thursday, the judge said Waitokia, like other youths, would visit Mr Richardson to sell him stolen property and carry out odd jobs for money.
He said Waitokia had gone to the Upper Riccarton house on August 1, 2015, with the aim for stealing from Mr Richardson or robbing him.
Outlining Waitokia's personal circumstances, the judge said he had been exposed to violence, gang culture and criminal offending in his childhood and teenage years.
Waitokia had used cannabis and alcohol since his pre-teen years, and had a history of suffering periodically from lowered mood and suicidal thinking.
The court was told that Mr Richardson had joined the British Army after leaving school and, after migrating to New Zealand, worked in the prison service.
At the time of his death, he had become something of a recluse and a hoarder.
People who had been his neighbours for 20 years spoke of him as a kindly man up until his psychological state deteriorated around five years ago.