The Independent Police Conduct Authority has cleared two officers of misconduct in relation to the fatal shooting of Steven Wallace in Taranaki nine years ago.
Mr Wallace was shot in Waitara on 30 April 2000 after he brandished a golf club and threatened to kill an officer.
The IPCA made public its findings on Tuesday. It found that Senior Constable Keith Abbott and Constable Jason Dombroski were justified in arming themselves in response to a series of violent attacks by Mr Wallace directed at property and people.
The authority says Mr Wallace has smashed the windscreen of a police car with a golf club, narrowly missing a constable's head, and had smashed the driver's window of a taxi, leaving the driver in fear for his life.
Mr Wallace had also driven at speed toward another person.
The authority says when the officers confronted Mr Wallace, he advanced rapidly towards them, armed with a golf club and a baseball bat, making threats to kill.
Senior Constable Abbott fired a warning shot and, when Mr Wallace continued to advance toward him, the officer then fired four shots at him.
Witnesses stated that Mr Wallace did not fall after the first two shots.
The authority found the officer was acting to defend himself and others, and his actions were consistent with police policy on the use of firearms.
IPCA chairperson Justice Lowell Goddard says Mr Wallace was shot, not because he had broken windows or because he was resisting or escaping arrest.
The judge says he was shot because Senior Constable Abbott had reasonable grounds to fear for his own life and for that of Constable Dombroski.
The authority found no evidence to support an allegation that Senior Constable Abbott had attended a social function on the evening before the shooting and had been drinking.
However, it has recommended that police adopt a policy on drug and alcohol testing of officers involved in critical incidents.
The authority also found there was a lack of communication between the officers before they confronted Mr Wallace, and that they technically breached police general instructions by not signing the Firearms Register when arming themselves.
But these breaches reflected the urgency of the situation they were responding to, it says.
The authority found that police should have done more to comfort Mr Wallace after he was shot, but expert medical opinion confirmed this would not have saved his life.
Questions remain, say family
The family of Steven Wallace says the IPCA report has failed to answer many of the family's questions over the death.
The authority found nothing to support suggestions from Mr Wallace's family that the officer who shot him had been drinking.
But Mr Wallace's mother, Raewyn, says Senior Constable Abbott was not breath-tested after the shooting, so the issue has not been resolved.
Police say they are working to introduce the compulsory drug and alcohol testing of officers after shootings or similar incidents.
Assistant Police Commissioner Viv Rickard says a new policy will be in place within the next few months to ensure that staff do not later face suggestions they were acting inappropriately.