Flatmate's jealous obsession ends in roadside stabbing of romantic rival

Andrew Howard Coyle became obsessed with his flatmate and wanted her to leave the father of her unborn child for him.

But instead of winning her over, Coyle ended up behind bars after confronting his romantic rival and stabbing him four times, including once in the head.

The attack played out on a West Auckland road in June 2024 after the two men spotted each other while driving, according to a recent Court of Appeal decision.

Coyle was later found guilty by a jury of wounding with intent to cause grievous bodily harm and was sentenced to five years and seven months’ imprisonment.

He went on to appeal his conviction and his sentence.

Coyle argued his conviction was a miscarriage of justice because evidence relating to a previous conviction of the victim was wrongly excluded at trial, and he challenged the sentencing judge’s finding that the case did not involve excessive self-defence.

But the Court of Appeal has rejected both arguments and upheld the conviction and sentence.

The decision stated the Crown case was that Coyle had become “obsessed” with his flatmate and was jealous of her partner, who was later stabbed in the confrontation.

At the time, the couple’s relationship had been described as “on and off”, but the woman had discovered she was pregnant with his child and intended to move back in with him once he found accommodation.

She had been living in a Glen Eden flat with three other people, including Coyle.

Coyle claimed he and the woman had been involved in a sexual relationship, which she denied.

The woman said Coyle had shown a romantic interest in her and wanted her to leave the victim.

According to the decision, the relationship between Coyle and the woman deteriorated after a dispute involving damage to each other’s vehicles.

Coyle moved out, and then in the days before the stabbing, he began sending the woman abusive messages and repeatedly demanded she provide the victim’s contact details so he could beat him up.

The decision stated Coyle’s threats included promises to “rearrange this c***’s face”, “break this c***’s ribs” and “smash his f***ing kneecaps out”.

The victim was unaware of the threats made.

Roadside confrontation

On June 7, 2024, he had been visiting the woman at the flat.

After she left for the shops with a friend, he remained nearby in his car and later noticed Coyle driving past.

Because the woman had previously said Coyle was not supposed to be around the property, he phoned the woman to let her know.

The victim then waited a short time before leaving, “to put some space between him” and Coyle.

The Oates Rd area in West Auckland, near where a confrontation between Andrew Howard Coyle and his romantic rival ended in a stabbing.

But as he drove along West Coast Rd and towards Glendale Rd, he noticed Coyle again.

When he saw Coyle pull into a shopping area near an ATM he intended to use, the victim decided to keep driving rather than risk running into him.

According to the decision, Coyle then did a U-turn and ended up behind him.

The victim said Coyle appeared to be “flying up behind” his vehicle.

At a nearby roundabout, Coyle overtook him and pulled in front of him on Oates Rd before getting out of his vehicle. The victim got out too.

The victim said in evidence he thought the confrontation would be verbal.

Instead, he said Coyle grabbed him in what he described as a “tight and aggressive rugby-tackle-type hug around his waist”.

He then stabbed the victim three times in the back and once in the head.

The attack lasted only seconds and Coyle fled the scene, leaving the victim bleeding heavily.

The man managed to drive back to the woman’s flat, an ambulance was called and he was admitted to hospital.

Coyle did not deny the stabbing and instead claimed he had acted in self-defence.

In a police interview later played to the jury, he alleged it was the victim who had pursued him and that the victim had got out of his car carrying a metal bar.

Coyle said he grabbed a multi-tool before confronting him because he feared for his safety.

However, a jury ultimately rejected his claim that the stabbing was in self-defence.

Appeals fail

On appeal, Coyle’s lawyer argued the trial judge should have allowed evidence that the victim had a previous conviction for wilful damage after smashing the rear window of the woman’s car with a baseball bat during an argument in 2023.

The defence argued the evidence could have supported Coyle’s claim that he believed the victim posed a threat.

But the Court of Appeal was not persuaded, finding the earlier incident had only marginal relevance because it involved property damage rather than violence against a person, happened more than a year earlier, and was unknown to Coyle at the time of the stabbing.

The court also rejected arguments that Coyle’s offending should have been treated as excessive self-defence.

It found there was sufficient evidence to support the sentencing judge’s conclusion that Coyle had pursued the victim, initiated the confrontation and acted as the aggressor.

The court pointed to Coyle’s threats of violence in the days before the stabbing, his driving behaviour immediately before the confrontation and the lack of evidence supporting his claim that the victim was armed.

As a result, the appeals were dismissed.

Tara Shaskey is an assistant editor and reporter for the Open Justice team. She joined NZME in 2022 and has worked as a journalist since 2014.