An Auckland man who killed his former boxing trainer and then tried to blame his mate for the murder has been sentenced to life with a non-parole period of 17 years.

Sean Hayde appeared for sentence today in the Auckland High Court before Justice Geoffrey Venning after he was found guilty last year of killing Wiremu Arapo nearly four years ago.

He was also found guilty of perverting the course of justice by setting fire to Arapo’s flat, and of a brutal assault on his ex-partner, for which he was on bail at the time of the murder.

During his time on electronically monitored bail while awaiting trial for the murder, Hayde fathered a child with a woman who became a pivotal figure at his trial as a source of his violent jealousy towards Arapo.

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Justice Venning sentenced Hayde to life with a minimum period of imprisonment of 17 years. A concurrent sentence of six years was imposed for perverting the course of justice, and six months for assaulting and threatening his former partner.

His childhood friend Gregory Hart was earlier sentenced to 11 years for manslaughter and perverting the course of justice for helping Hayde kill Arapo and burn down the house in a futile attempt to destroy evidence.

Justice Venning said Hayde continued to minimise his responsibility for his offending in comments to a clinical psychologist who prepared a report ahead of sentencing.

The psychologist said Hayde was “cold and unfeeling” and made those around him uneasy.

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Arapo’s mother spoke at the hearing and described Hayde as cowardly for beating Arapo to death when the skilled boxer and Army veteran was outnumbered, then burning his home and body.

“We will never, ever forget Wiremu and he will live on in our hearts and memories forever,” she said.

“In time our pain will ease and you will be forgotten by us but you will always be labelled as Sean Hayde, murderer.”

Crown prosecutor Ned Fletcher sought the 17-year non-parole period that can be imposed for especially cruel, callous or barbaric murders.

Hayde’s lawyer Emma Priest said he did not intentionally kill Arapo but was simply drunk and reckless. Setting the fire was an impulsive decision borne out of panic, she said.

Officer in charge of the investigation into Arapo’s death, Detective Inspector Warrick Adkin of Counties Manukau CIB, acknowledged Arapo’s whānau and the investigators who brought the pair to justice.

Arapo’s family and friends sat through the trial and were told lies by Hart before his arrest as he tried to paint the fire as accidental.

“They have shown great courage and strength since his life was needlessly cut short at the age of 27,” Adkin said.

“The Operation Bancroft team did an outstanding job and showed great professionalism to ensure we could achieve justice for Wiremu.”

Deadly web of jealousy fuelled murder

The killing was the result of a tangled web of jealousy, infidelity and resentment, the Crown said.

Hayde and Hart each denied charges of murder and perverting the course of justice.

They blamed each other at their trial, each trying to pin sole responsibility for the killing on the other man. But the jury was not convinced by either man’s version of events.

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After a 3½-week trial in the High Court at Auckland, the jury found Hayde guilty of murder but Hart guilty of the lesser charge of manslaughter on October 6.

Both were also found guilty of attempting to pervert the course of justice by setting the Minerva Tce home alight.

Arapo was once Hayde’s boxing trainer and friend but the pair were cast as love rivals in the trial, both vying for the attention of the same woman. Hart was Arapo’s flatmate.

Arapo, 27, was described as a popular and outgoing man who left behind a fiancé with whom he was planning to start a family.

Both men pleaded not guilty and gave evidence to describe two differing versions of how Arapo was killed.

Hayde’s version described Hart telling Arapo, a fellow army veteran, “Goodbye brother” before stabbing him in the neck.

His story was skewered by the prosecution and Hart’s defence team as something out of an overwritten movie script.

Sean Hayde claimed his co-accused Gregory Hart was solely responsible for killing Wiremu Arapo. The jury did not believe him and found him guilty of murder. Photo / Jason Oxenham

Hart’s simpler and less filmic version had Hayde kicking Arapo to death.

Hayde’s alleged attack on his former partner has been characterised as a prelude to the killing of Arapo five weeks later.

Crown prosecutor Fletcher described the killing as the crescendo of rising tensions driven by a tangled web of resentments and infidelities.

“This is a case about relationships, relationships gone wrong, and their snowballing effects,” Fletcher said.

Forensic evidence showed Arapo was dead before the fire started. A lack of carbon monoxide in his blood, or burns to his trachea, showed he had not been alive to inhale smoke.

Damage to his hyoid bone, a small, mobile structure in the throat that is typically broken only in hangings or strangulations, suggested he had been throttled. The Crown said the pair used petrol to burn down the house.

Traces of petrol were found on one of Hart’s shoes left at the scene and an empty petrol can was found in Hayde’s car. The fact that the fire was contained to Arapo’s wing of the home was evidence an accelerant was used, the prosecution claimed.

“Either both or one of the defendants killed him,” the judge said in summing up the case.

The Hayde and Hart defence teams had, in effect, a dual role as prosecutors. Each tried to prove that not only was their client not guilty but that the other man was the killer.

Gregory Hart (left) in the dock on the first day of the trial, alongside a security guard. The jury found him guilty of manslaughter. Photo / Jason Oxenham

The pair, who had been friends since the third form at St Peter’s College in Epsom, did not speak to or look at each other as they sat together in the dock, separated by security guards.

The Crown said both men went to Minerva Tce to, at the very least, give Arapo a serious hiding, and both men killed him before setting the home alight in a bungled scheme to destroy the evidence.

Each had a clear motive to kill Arapo, the prosecution said.

Hayde had a blossoming relationship with Jenifer McManus, a friend of Arapo. Hayde’s relationship with her began as an affair while he was still with the woman he was charged with attacking.

It later emerged Arapo and McManus had gone beyond friendship a couple of times, before her romance with Hayde.

Hayde was jealous of Arapo’s continued closeness with her, Fletcher said.

Jurors were shown this computer-augmented fly-through of the MInerva Tce rental in Cockle Bay where Wiremu Arapo's body was found after a fire. Photo Supplied / NZ Police

For his part, Arapo came to take a dim view of the budding romance, especially after the domestic violence allegations emerged and after comments Hayde had made about a neighbour he viewed as attractive.

“Mr Hayde’s hatred, jealousy and paranoia of Mr Arapo came to the boil,” Fletcher said.

“He hated Mr Arapo because he was jealous and suspicious of his friendship with Jenifer McManus and on 20 October that hatred was set to explode.”

Key to both the Crown and Hart cases was a threat made by Hayde to his former partner seven weeks before Arapo’s death.

The woman said he threatened to kill her and burn down her house – the very thing the Crown and Hart’s lawyer Paul Borich KC said came to pass on October 20.

“If Sean Hayde is telling you the truth, he would have to be the victim of the cruellest coincidence in history,” Borich said.

George Block is an Auckland-based reporter with a focus on police, the courts, prisons and defence. He joined the Herald in 2022 and has previously worked at Stuff in Auckland and the Otago Daily Times in Dunedin.