Arthur Easton was killed in 1985, but the search for his killer continues. Photo: Supplied / Police
A private investigator who helped prove Alan Hall's innocence believes others know the identity of Arthur Easton's true killer.
The nearly 40-year-old case has been re-opened after Hall - who was originally found guilty of murder - had his conviction overturned.
Easton, 52, was stabbed to death by an intruder who broke into his Papakura home in October 1985.
Police are now offering a $100,000 reward for anyone with information leading to a conviction, along with immunity for anyone who had assisted or protected the killer.
Tim McKinnel Photo: RNZ / Cole Eastham-Farrelly
Tim McKinnel, a private investigator who worked on Hall's case, believed there were people in the Papakura community who knew the killer's identity.
"It's undoubtedly true there will be people in the community who know who killed Arthur Easton," he said.
"In our work reviewing and executing the wrongful conviction case for Alan, we formed our own views on what might have happened, and certainly there's the possibility other people were involved with the main offender."
He said police were keeping Hall and his family in the loop as the investigation unfolded.
Police offer reward for info on Arthur Easton murder
"Alan is well aware of what's going on, he and his family have had a good relationship with the police over the last 12 or 18 months and they've been kept up to date and informed as to what police are doing," he said.
"Alan is very eager for Arthur Easton's killer to be caught. It's an incredibly painful situation to be in, sitting in prison for a murder you didn't commit knowing the person who did commit it has faced no accountability. This is an opportunity to find who did kill Arthur and bring some accountability."
But McKinnel said the police would have a difficult time investigating a murder so long after it was committed.
"When you're trying to solve a murder that's nearly 40 years old it's a complex investigation by its very nature," he said.
"It won't be easy, but it is possible and police obviously think offering a reward is an appropriate tactic."
Alan Hall's brothers Greg, Geoff and Robert speak outside the Supreme Court in 2022. Photo: RNZ
Hall's brother, Geoff Hall, told Morning Report the Police Commissioner notified the family of the reward when he met with them to apologise for the wrongful conviction.
It was something they were in support of and thought it was a "good idea".
Geoff Hall said a resolution for Easton and his family was what they wanted to see and would bring an end to the ordeal they have dealt with.
"A conviction for Arthur's murder would be absolutely amazing.
"For the Easton family, it would be wonderful."
McKinnel told Morning Report he would be watching keenly for any updates in the investigation while the reward was in place.
A conviction for Easton's murder was the "last piece of the puzzle" and the Hall family was keen to see it completed, he said.
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