Roadworker George Taiaroa was sought out and targeted by his murderer, police say.
They also believe they know the "misguided'' motive for the murder, labelling it "beyond comprehension'' and saying it would appall most people.
Addressing a throng of media in Rotorua this afternoon, Detective Inspector Tim Anderson said he would not go into detail about what police believed the motive to be, but said police were appealing to anyone harbouring Mr Taiaroa's killer to come forward.
He warned that protecting the murderer was tantamount to pulling the trigger, and said those who were assisting the suspect had misplaced loyalty and he urged them to come forward.
Police were keeping an eye on a handful of people in connection to the shooting, Mr Anderson said.
Mr Taiaroa was shot dead as he operated a stop-go sign on Tram Road at Atiamuri in Waikato on March 19.
Mr Anderson said police believed Mr Taiaroa was sought out and targeted by his killer.
"However we do not believe that George or his family knew his killer. There is no evidence that this was a case of mistaken identity.''
Police knew where their suspect was and had spoken to the man as part of their investigation, Mr Anderson said. He would not say whether the man was known to police before the fatal shooting.
He said the suspect was a cold blooded killer and the shooting was planned, thought through and targeted. He believed no one else was in danger.
Mr Taiaroa's family were being kept well informed about the progress of the investigation and were staying very strong.
Mr Anderson said no arrests had yet been made.
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