It is always sickening to realise someone has got away with murder. It might not be such a surprise when a body is found well hidden long after the event, but that can not be said of the murder of Claire Hills, now 20 years ago. Her killer was seen setting fire to the car in which her body was found on Mangere Mountain.
It was 5.45am, dawn was breaking. Unseen, a woman noticed the man acting strangely around the car. As she watched the car burst into flame and the man ran towards her.
She clearly saw his face before he saw her, stopped, turned and ran in the opposite direction. Then a jogger in the domain saw him, then a taxi driver on the motorway, and another motorist saw a man of the same description walking towards the Mangere Bridge shops.
Then he vanished.
A post mortem examination showed Hills had died in the fire, there was soot in her lungs. There was evidence she had been sexually assaulted.
Nothing found in or around the car could have been used to set it on fire. The killer must have bought or stolen a container of fuel. The police have a sample of his DNA but over 20 years a matching sample has not turned up in their database.
Yet somebody knows him, probably quite a number of people know him, not as the killer perhaps but as somebody who they know was in the vicinity at the time.
Hills worked for McDonalds at the airport. She was due to start her shift at 2.30am that day. She never arrived. Chances are she met her killer sometime after 2am. Whatever happened in the three hours before her death remains a mystery to the police.
The file remains open under the eye of Detective Superintendent Dave Lynch, in charge of all major criminal investigations in Auckland and Northland.
"I'm still convinced there's a person or small group out there that know, or have very strong suspicions around what happened," he says. "I always hold out hope one day someone will pick up the phone."
It might even be the killer himself, 20 years older. He did not kill the woman who saw him that morning, he has left no other trace of his DNA in the New Zealand or Australian criminal databases. If he hasn't killed again he may be haunted by this one every day.
If so, he will find no release until he picks up the phone.