A police officer who shot and injured a man in Blenheim a year ago has been cleared of wrongdoing.
The Independent Police Conduct Authority report released today found the use of force was justified in what was a life-threatening situation.
Police said they acknowledged the finding about a "fast-moving situation" on Sunday, 28 July last year.
The man had threatened a woman and her daughter with a knife, then stole their car. Police pursued the car for 12km, using road spikes to stop it.
The officer got out of his patrol car, leaving the keys in the ignition and the engine running. He drew his Glock pistol and repeatedly told the man to drop his knife.
The man continued towards him so the officer fired a shot, which hit the man's arm.
The man then got into the patrol car's driver seat, revved the engine, and tried to get the car into gear. The officer presented his pistol at the man through the closed window and told him to get out and onto the ground.
The man complied, was arrested and received medical treatment.
IPCA chair Judge Colin Doherty said the officer fired the shot to defend himself in a life-threatening situation.
"We found that the officer involved here was involved in a situation where he had to act quickly and get out of his patrol car to apprehend the person who had been stopped.
"This person had been involved in an aggravated robbery where he used a knife to hold up a woman and her daughter and steal their car."
Judge Doherty said despite warnings from police to the man to stop, he did not. He said the officer was found to have acted in self-defence when the man continued to advance, looking as though he was going to stab or cut him, therefore injure or potentially kill him.
"We found he was justified in shooting at the assailant."
Judge Doherty told RNZ that despite being incapacitated to some extend by the bullet wound to his arm, the man was still able to try to steal the patrol car before the officer could prevent it.
Police have since identified actions to minimise the chance of offenders gaining access to police vehicles and firearms.
Acting Tasman District Commander Freda Grace said communication had no effect on the man's behaviour and the officer genuinely feared for his life.
"Use of force by police officers is always a last resort.
"This was a fast-moving and evolving situation, in which the officers involved made judgement calls that were supported by the IPCA.
"In this instance, the IPCA noted that communication had no effect on the man's behaviour and the officer genuinely feared for his life, and fired a shot in self-defence."
Grace said officers' safety was paramount and all needed to be safe while out doing their job.
Judge Doherty said the law relating to self defence applied the same to police as it did to the public.
"Police are able to defend themselves and use reasonable force to do so - that's how we assess it, we look at each one (incident) on its merits. We look at the facts and then apply the law."
He said almost all cases were fast-moving situations that required the police to act quickly and to the best of their ability, but within the law.