Teenager Ariki Rigby was murdered because of a Mongrel Mob t-shirt. 

Today the man who killed her, Jimmy Heremaia, pleaded guilty to murder, meaning the full story about what really happened to Rigby can finally be told. 

Heremaia had been “de-patched” by his gang chapter after Rigby was seen wearing the t-shirt in public. 

This was against the “gang code”, the High Court at Napier has been told. 

Heremaia appeared via AVL and pleaded guilty to Rigby’s murder in the court on Friday, allowing the story of her death - which had previously been suppressed - to be told. 

Rigby died on or about September 2, 2022. Her body was found in a burned out car in a riverside car park near Havelock North three days later. 

Heremaia, whom she had known for a few weeks, bashed her in the head with her own hammer, which she had brought with her for self-defence. 

Heremaia, who was 32 years old at the time, was a patched member of the Flaxmere chapter of the Mongrel Mob. 

Between August 29 and September 3, 2022 Herema was driving back and forth between Wairoa and Napier in a grey Toyota sedan. He had borrowed it from his Mob captain on the pretence of needing a car for work. 

On one of these journeys, Ariki Rigby travelled with him. Some time in the last two days of August, she came into possession of the t-shirt. 

In the early hours of August 31, Rigby was seen by another patched Mongrel Mob member wearing the shirt in public in Hastings. 

Gang regalia is subject to rules. Allowing anyone else to wear it is seen by members as a serious violation – particularly if the non-gang member wearing it is female. 

In the words of a Crown summary of facts presented to the court: “Ms Rigby being seen wearing the Mongrel Mob t-shirt was the catalyst for the events that followed, and led to her death.” 

On September 2, Heremaia’s sister sent him a text message to say that his Mongrel Mob patch had been removed from the family home. 

“The removal of Mr Heremaia’s patch meant that he had been ‘de-patched’ from the Mongrel Mob because of the incident involving Ms Rigby and the Mongrel Mob t-shirt,” the summary of facts said. 

About 9.52 that night, Heremaia met Rigby in Onekawa, Napier and she got into his car. 

They drove to Bay View north of the city, where they parked up. 

Rigby had a hammer with her as she feared for her safety. 

They argued and she swung the hammer at Heremaia. He blocked her, overpowered her, took the hammer from her. 

He hit her twice in the head, causing skull and brain injuries which led to her death. 

Later, with the help of a friend Ropine Paul, Heremaia drove the car to the Havelock North car park and burned it. 

Ric Stevens spent many years working for the former New Zealand Press Association news agency, including as a political reporter at Parliament, before holding senior positions at various daily newspapers. He joined NZME’s Open Justice team in 2022 and is based in Hawke’s Bay. His writing in the crime and justice sphere is informed by four years of front-line experience as a probation officer.