The detective heading an investigation into the killing of an elderly woman in Auckland says he is still confident of a breakthrough in the hunt for her killer.
Yan Ping Yang, 80, was beaten unconscious in her Manurewa home four months ago and died later in hospital.
Detective Inspector Mark Gutry says the killer, who is believed to have been a burglar, may have spoken to someone about the attack.
He says the police have interviewed several thousand people and have almost completed going through a list of about 100 people of interest.
Detective Inspector Gutry says the 10 officers still on the case are waiting for forensic results, and he believes the methodical investigation will lead them to the culprit.