In the dead of night at a remote campground, Adrian Humphreys stumbled out of his camper and scrambled for help.

He was “howling” and bleeding profusely from five stab wounds to his torso. But Humphreys, 57, never found help and only 20 metres from his campsite, he fell to the ground and died.

Nearby, a 17-year-old allegedly ditched the knife and then scuttled back to his pup tent.

That teen, Justice Williamson-Atkinson, is now defending charges of burglary and murder in a trial which began on Monday in the High Court at New Plymouth before Justice Francis Cooke.

On Tuesday, Crown prosecutor Jo Woodcock gave an opening address to the jury in which she alleged the teen and one of his friends had broken into Humphreys’ camper for the purpose of stealing his car.

Woodcock alleged that during the course of the burglary, Williamson-Atkinson, of Hastings, had stabbed Humphreys to get the keys, or to avoid detection for that offending.

But defence lawyer Matthew Phelps claimed it wasn’t Williamson-Atkinson who killed Humphreys.

He alleged it was actually his client’s friend who committed the act.

The jury heard the teens had been staying at Bushlands Campground in Tāngarākau, eastern Taranaki, as part of the at-risk youth programme, Start Taranaki.

They arrived on May 6, 2022, with another teen participant and three of the programme’s mentors.

Humphreys, an outdoor enthusiast from Rotorua, arrived that same day.

He had just bought a camper trailer and was excited to take it to Bushlands Campground, along the Forgotten World Highway, where he had stayed only weeks prior.

The manager of the campground welcomed Humphreys when he arrived and explained that the youth programme, which she had hosted for around five years, would also be staying at the site.

She told him there was nothing to be worried about as the teens were well-supervised but warned him to remove any “temptations”.

Around 6.30am the following morning, Humphreys’ body was found by two of the programme’s mentors as they made their way to the campground’s kitchen.

Originally from the United Kingdom, Humphreys was an anaesthetic technician who worked at Southern Cross Healthcare in Rotorua.

Woodcock said he had simply found himself “in the wrong place at the wrong time”.

She alleged Williamson-Atkinson and his friend from the programme, whose name has been suppressed, had had enough of rural Taranaki so they created a plan to steal a car and leave.

Around 1am on May 7, 2022, they snuck out of their tents and put their plan into action.

Williamson-Atkinson, allegedly armed with a knife he had taken from the communal kitchen earlier, entered Humphreys’ camper and tried to find the keys to his SUV.

Unable to find them, he took Humphreys’ wallet and cell phone instead and allegedly stabbed him a number of times.

The teens left the camper and Humphreys staggered out behind, desperate for help.

With no way to leave the campground, the teens returned to their tents.

Woodcock said the Crown planned to call 40 witnesses throughout the course of the four-week trial.

Evidence would be heard from other campers who reported hearing sounds around the time Humphreys was killed.

Noises such as a “yell”, “howling” and a “high-pitched scream” were likely to have been Humphreys calling for help, Woodcock told the jury.

She said forensic evidence would show Humphreys’ DNA was found in bloodstains on a jersey in Williamson-Atkinson’s tent, and that fibres from his pants were located outside Humphreys’ camper.

While the murder weapon has never been found, Woodcock pointed to evidence indicating Williamson-Atkinson had thrown it in a river.

Woodcock alleged Williamson-Atkinson had confessed the killing to a small number of people but his lawyer, Phelps, said this never happened.

Williamson-Atkinson told the police he was not responsible for the death of Humphreys and that it was, in fact, his friend who was to blame.

“Justice told the police that he was not present in the room at all when Mr Humphreys was stabbed,” Phelps told the jury.

“[But] he does accept that he had arrived shortly thereafter to find that [his friend] had stabbed Mr Humphreys.”

On day two of the trial, Williamson-Atkinson, dressed in a suit and tie, wrote note after note which he then passed to a communication assistant sitting next to him.

He will have the specialist help for the duration of the trial to ensure he understands the court proceedings.

Among the first of the Crown witnesses called, Start Taranaki youth worker Kajin Phillips gave evidence about the relationship between Williamson-Atkinson and the other teen.

Phillips said the other teen was “the leader” in terms of the hierarchy of the programme’s participants, and that Williamson-Atkinson appeared to be scared of the teen and would often follow his lead.

But after Humphreys’ death, that dynamic had changed and the two boys “were on the same level”, Phillips said, referring to the pecking order of the teens.

The jury heard that on May 18 last year the pair stole a car from Start Taranaki and drove it to Auckland, where they were arrested for the theft.

Tara Shaskey joined NZME in 2022 as a news director and Open Justice reporter. She has been a reporter since 2014 and previously worked at Stuff where she covered crime and justice, arts and entertainment, and Māori issues.