Convicted murderer and samurai swordsman, Antonie Ronnie Dixon has been jailed for life with a minimum of 20 years.

Dixon was called a "cold-blooded and utterly callous" killer by Justice Judith Potter passing sentence in the High Court at Auckland this morning.

Dixon was found guilty by a jury in March of murdering Auckland man, James Te Aute with a home made machinegun, and using a samurai sword to wound Simonne Butler and Renee Gunbie in Pipiroa near Thames on the Hauraki Plains in January, 2003.

The jury decided he was not guilty of trying to murder the two women.

He was also found guilty of shooting at police, kidnapping and aggravated burglary.

The jury rejected his defence that he was insane and did not know his actions were morally wrong.

Crown prosecutor Simon Moore said Dixon was on a P-fuelled crime spree and knew exactly what he was doing every step of the way.

He said the convictions sent a strong message that methamphetamine did not equate to criminal insanity.

Her said it was probably the first big trial where P had been involved and the judge had said the consumption of P on its own, even if it might induce a psychosis, was not enough to amount to insanity under the Crimes Act.

After the convictions Detective Inspector Bernie Hollewand, who led the inquiry, said P was "just another intoxicant and people are going to be held accountable for their actions whether or not they are using P".

Dixon, 37, looked relatively relaxed as he entered the court with three security guards.

The wild, wide-eyed look he displayed throughout much of his trial was missing and he smiled at a person in the public gallery as he entered the dock.

During his submissions Mr Moore said there was a high level of violence and premeditation through the attacks and the killing of James Te Aute was a way of attracting police attention.

"It was a device and Mr Te Aute provided the focus for that device."

Mr Moore said it was difficult to imagine a more calculated or callous killing "where the identity of the target was of no relevance at all" to Dixon.

Mr Te Aute was in the wrong place at the wrong time, he said.

There was no mitigating feature, and no hint of remorse. Dixon had said he was thoroughly justified in what he did.

Mr Moore said it was truly an execution-style killing.

He said a minimum non-parole period of 20 years was appropriate at which point Dixon interrupted from the dock.

"Bring back the electric chair," he said and applauded.

For Dixon, Barry Hart said even though the jury found him not insane he had more than personality problems.

"It's a mental disorder.

"I am surprised the Crown can't give at least some recognition to the mental problems this man has had.

"Your honour ought to give substantial weight to his mental problem," Mr Hart told Justice Potter.