People in Opotiki with clues to the brutal killing of an elderly man last month have been urged to break their "code of silence" and put the killer behind bars.
Police said someone would know who bashed 78-year-old John Rowe to death in his Opotiki home on November24.
However, a misguided "honour among thieves" code may be persuading them not to go to police.
"There is a certain code of silence that people who are linked to people who have committed offences like to keep," said Detective Inspector Rob Jones.
"They have real reservations about breaking their silence and it is up to us to try and encourage them to do that."
People who knew the killer had to understand they had someone in their community responsible for "bashing to death a 78-year-old victim", Mr Jones said.
"I am not sure why anyone would think you would want to keep silent about something like that.
"It is far better to be a witness than become a suspect."
"If you are sitting on something you know is important for police to know, why do you keep concealing it?" Mr Jones said.
Mr Rowe was doing nothing that would have caused anyone any concern, he said.
"He was just an elderly man minding his own business, getting on with his life as best as possible."
Two weapons sent for forensic analysis were almost certainly used in the killing but that had yet to be confirmed, Mr Jones said.
Police had a list of "people of interest" which was being worked through by the 30-strong team hunting the killer.
"We are still working through a process of elimination."
He would not say if the list was getting bigger or smaller.
He was reluctant to instil fear into the town that the killer would strike again.
"You can never discount that someone who is responsible for an attack like that will not do something like this again in the future or hasn't done so previously."
However, he said he had always been confident the killer would be caught.
