A man who strangled an Upper Hutt woman in her home in 2012 has been jailed for life and ordered to spend at least 12 years behind bars.
Kharn Tamaka, who is 29, was sentenced in the High Court in Wellington on Tuesday, having earlier pleaded guilty to Mary Donnelly's murder.
Statements read to the Court by members of Ms Donnelly's family described their loss, along with their horror and disbelief that a vulnerable woman with disabilities could be killed in such a way.
Justice Ronald Young described Ms Donnelly's killing as shocking.
He said as well as strangling her, Tamaka had also inflicted other injuries on her which would have caused considerable pain, and there was also a sexual element to the attack.
He said Tamaka had a history of aggressive sexual behaviour, starting at the age of eight, and has been assessed as being at high risk of reoffending.
Justice Young said it was worrying that Tamaka's offending had become progressively worse.
He acknowledged Tamaka had a degree of intellectual impairment, and had suffered a miserable childhood.
Detective Senior Sergeant Dave Thornton says information from the public and CCTV footage were helpful but it was science that ultimately led to Tamaka's arrest.
Tamaka initially denied knowing Ms Donnelly but his DNA was located at the murder scene.
Detective Senior Sergeant Thornton says Tamaka lived five kilometres away from Ms Donnelly but her DNA was also found on a t-shirt at his home.