It will be a year on Wednesday since grandfather George Taiaroa was fatally shot as he operated a Stop-Go sign at roadworks in Atiamuri and police believe they have the right suspect.
Although no arrest has yet been made, the police investigation has made positive steps in the last 12 months and its belief in the theory behind the murder has not wavered.
Detective Inspector Tim Anderson said: "It has been important for the integrity of the investigation from the outset to be patient, thorough, and methodical, and to explore every possible avenue. We continue to do that and every avenue we have taken during the last year has simply reinforced our belief about what happened that day and why George was murdered.
"We still believe that the blue Jeep Cherokee vehicle we seized in the weeks following the murder was involved. We still have that vehicle and we are continuing to carry out work with that vehicle as part of the investigation. Although I am still not prepared to discuss the motive for the murder; our position on that, and the fact that it would appall any reasonable person, has not changed.
"My position also remains the same when it comes to not making comment on individuals; but we still have one prime suspect."
Police want to make clear to the public, the person responsible and anyone else who knows or suspects who was involved, that the investigation is still very much active.
"The last year has not been easy for George's family and this week will no doubt be particularly difficult. He was a doting family man and the impact of his loss is never far from our minds; it drives us forward and makes us all the more determined.
"As the Taiaroa family has its own private reflection, we ask that the public also reflect on this case and contact us with any information they might have. It doesn't matter how much time has passed or how irrelevant it may seem, it may be important."
It has previously been reported in the media that the main suspect is Quinton Winders, who lives in Taranaki.
Anyone with information is asked to contact the investigation team on 0800 Kingswood (0800 546 479). Information can be also provided to the organisation Crimestoppers on 0800 555111.