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Home / New Zealand

Whenuapai homicide: Five years' prison ordered for man who fatally stabbed former friend

Craig Kapitan
By Craig Kapitan
Senior Multimedia Journalist·NZ Herald·
13 Dec, 2021 11:24 PM5 mins to read

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Armed police outside the Trig Rd property where Coubin Tamatoa was killed last year. Photo / Dean Purcell

Armed police outside the Trig Rd property where Coubin Tamatoa was killed last year. Photo / Dean Purcell

A drug dealer who stabbed his former friend to death lifted both arms in the air as if in victory on Tuesday as he limped out of the courtroom to start serving a five-year prison sentence.

Prosecutors had accused Isaac Allen Harnwell, 34, of murder when his trial began at the High Court at Auckland in early August. But jurors acquitted him of that charge and instead issued a guilty verdict for manslaughter nearly two months later, following a lengthy break in the trial caused by the Covid-19 lockdown.

Harnwell's lawyers had argued he acted in self-defence when he twice stabbed Coubin Tamatoa, 31, at a rural Whenuapai property in August 2020 after hours of hiding from Tamatoa in a bedroom. The first cut to Tamatoa's eye was non-fatal, but the next one penetrated his ribs and heart - the force so severe that the handle to the kitchen knife broke off from the 20cm blade.

At the sentencing hearing on Tuesday, Justice Mathew Downs acknowledged the uniqueness of the case, which he characterised as "excessive force in the context of self-defence".

"Mr Tamatoa was violent and erratic that evening," he acknowledged of the victim.

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Downs said he accepted that Harnwell was trying to hide after Tamatoa had threatened violence against him and even had a friend block the driveway so Harnwell couldn't leave. But the evidence suggests Tamatoa was unarmed when he entered the bedroom where he was killed, Downs said, pointing also to the defendant's multiple prior convictions for family violence.

"I am not persuaded by the existence of tangible remorse," Down added before announcing the five-year term.

Jurors were told during the trial that Harnwell went on the run after the homicide. Armed police located him a week later, hiding inside a ceiling cavity at an Onehunga home.

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The High Court heard Isaac Allen Harnwell emerged from a ceiling cavity "manhole" in an Onehunga building. Photo / Google
The High Court heard Isaac Allen Harnwell emerged from a ceiling cavity "manhole" in an Onehunga building. Photo / Google

Harnwell didn't testify during the trial, but he told police in an interview that Tamatoa fell face-first onto the knife as the two tussled on a rocking chair - a contention the judge described Tuesday as "plainly untrue". Harnwell also insisted during the police interview that he wasn't responsible for the chest wound and that someone else must have done it.

During the trial, both prosecutors and the defence agreed that Tamatoa's behaviour on the evening of his death was appalling. Witnesses said Tamatoa put a gun to his ex-girlfriend's throat, he got in a fistfight with another man and he voiced loudly his desire to harm Harnwell.

Defence lawyer Andrew Speed described his client as "terrified" and the victim as a deranged criminal and a "very nasty man bent on very serious mischief".

But Tamatoa's family and friends painted a much different picture of him on Tuesday as they stood to deliver victim impact statements.

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"There's pain every minute thinking about how he died, about how much I miss him," said his mother, Michelle Makaea - her hands that held her printed statement trembling as she pushed through tears to continue reading it. "My heart is shattered into a million pieces."

Harnwell wouldn't make eye contact as she spoke. He rocked in his chair, his head barely visible as he looked into his lap for part of the statement. Later, as the mother of Tamatoa's four children spoke, he wiped away tears.

"Where's Daddy, Mama?" Zhaqia Maaka recalled their 3-year-old son sometimes asking her, adding that she never knows what to say "because he's too young to process the hurt".

"I wouldn't wish this upon any of my worst enemies," she said. "I hope one day you truly understand the devastation you have put on me and my family."

Tamatoa's older sister, Leanne Trego, said the death has left the entire family feeling vulnerable and scared to face life without him by their side.

"He was a kind, loving, happy, humble and most of all caring brother," she said. "He had a smile that would light up the room."

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Crown prosecutor Alysha McClintock argued during the trial that rather than self-defence Harnwell was motivated by revenge over an $18,000 drug theft and prior bad blood between the two. The defendant was lying in wait rather than cowering, she suggested.

Taking the jury's verdict into account, it's possible that the first wound to Tamatoa's eye was self-defence, she conceded at the sentencing hearing. But that would have "disabled the threat posed", she told the judge, suggesting that the fatal chest wound that followed was something "more gratuitous" than simple self-defence.

Harnwell's lawyers disagreed, comparing the case to those of battered wives who kill their spouses.

They also filed with the court a report that explained how Harnwell, who uses two canes, was attacked and beaten in 2019. It resulted in post-traumatic stress disorder that influenced his response on the night of Tamatoa's death, a report suggested. He's been using methamphetamine since the age of 12 and appears to be addicted, the report also stated.

Justice Downs allowed for a six-month discount off what would have been a five-and-a-half-year sentence due to those factors.

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