A 13-year-old Taranaki boy is now believed to be New Zealand's youngest convicted murderer.
Jordan Nelson admitted murdering his caregiver, 50-year-old Rosemaree Kurth, when he appeared in the High Court at New Plymouth on Thursday.
He changed his not guilty plea ahead of a scheduled trial next week.
He was 13 years and 89 days old when he shot Ms Kurth in the back of the head with a .22 rifle as she did a jigsaw puzzle in the dining room of the Okoki farm house, west of Waitara, in April, the Taranaki Daily News reports.
He shot her while her partner, Kerry Lock, who Nelson considered a grandfather, was out walking his dogs.
Nelson dragged her into a bedroom and then took $16.10 in coins and a tusk carved necklace before driving away in Ms Kurth's car.
Mr Lock saw the car leaving and believed it was Ms Kurth going to Urenui, but then found her body in the bedroom.
Police found Nelson in Waitara. He claimed to have a memory blank but later admitted he had shot Ms Kurth.
Crown solicitor Cherie Clarke said the the only motive they could find was that Ms Kurth had taken his Freeview TV receiver from him.
Nelson had initially denied the charge and was due to stand trial later this month, but on Thursday changed his plea.
Nelson will be sentenced next month.
The previous youngest murderer was a 13-year-old Wellington schoolboy, who in 1991 was convicted of the stabbing murder of nurse Rachel Bennett. He has permanent name suppression.