Retrial for Taranaki man accused of murdering his neighbour begins

Lachlan Johnson, of Taranaki, is defending a murder charge in the High Court at New Plymouth. Photo / Tara Shaskey

Mitchell Mosen may have been battling brain cancer but it was a gunshot wound to the chest that ended his life, despite his mother's best efforts to resuscitate him. Now, his neighbour is defending a murder charge.

When Lachlan Johnson arrived at the Mosens' rural Taranaki property armed with a loaded semi-automatic shotgun, he was enraged and looking for retribution, the Crown allege.

Johnson shot Mosen in the foot and then during a struggle between the pair, he pulled the trigger a further five times.

Four shots hit the porch but the fifth struck Mosen in the chest and ended his life shortly after.

The death was a calculated murder, the Crown allege.

But while defence accept that Johnson killed Mosen, lawyer Paul Keegan said it was without murderous intent and the death instead amounted to manslaughter.

On Monday, the retrial of Johnson began in the High Court at New Plymouth.

Prosecutor Justin Marinovich opened the Crown's case by telling the jury Johnson had killed Mosen in retaliation to an earlier altercation between the pair.

Mosen was battling brain cancer at the time of his death on August 22, 2020.

He was living with his mother, Patricia Mosen, at her Korito Rd home, about 20km from New Plymouth. Johnson lived within a kilometre on the same road.

Patricia is a nurse and had been caring for Mosen, her youngest child who had been undergoing radiotherapy in the lead-up to his death.

His personality had been impacted by the disease, leaving him frustrated, agitated and quick to become aggressive over trivial matters.

It was suggested that a minor matter, of Johnson lighting paper lanterns, had led to the altercation before Mosen's death.

Mitchell Mosen, 30, died as a result of a gunshot wound to his chest.

Around 6pm of that evening, Johnson lit and released a number of paper lanterns over a valley near his home.

Around that same time, Mosen left his property on a quad bike and soon crossed paths with Johnson.

Yelling began between the pair and quickly escalated to violence.

Mosen returned home after and was asked by Patricia, who had heard arguing, what had happened.

He told her he had "sorted it".

Meanwhile, Johnson was so "enraged" by the confrontation, he went to his house, grabbed his shotgun and then made his way to the Mosens.

There, he barged past Patricia who was standing at the front door and found Mosen in the lounge.

Marinovich said Johnson cocked his gun and pointed it at Mosen, who then pushed Johnson out of the house and onto the porch.

As this was happening, Johnson fired the gun and shot Mosen in the foot, leading to a struggle between the two.

Johnson then pulled the trigger a further five times, with the fifth hitting Mosen in the chest.

The gun then went quiet.

Mosen called for help and as Patricia phoned for an ambulance she began work to treat his foot.

But it wasn't immediately clear to her that he had also been shot in the chest, and as Johnson left the scene, he told her "I've only shot him in the foot. You're a nurse, you fix it."

While on the call to emergency services, Patricia found the second wound and her son then began to lose consciousness.

She began CPR and when police and paramedics later arrived, they took over.

But Mosen was pronounced dead at 7.55pm.

At his house, Johnson had left a note for his son saying "I just shot a dude, be good," before phoning police.

During that call, he said Mosen had "beaten the s***" out of him and that he then shot Mosen in the foot.

"I just saw red, I know I'm going to get in the s*** for this," he told the operator.

Marinovich alleged Johnson killed Mosen intentionally.

"It was calculated, committed in rage and done in retribution for an earlier confrontation."

Keegan told the jury a lot of evidence was largely agreed upon and they would need to focus on the very narrow issue of murder versus manslaughter.

"If we could plead guilty to manslaughter right now, we would and the case would be over," he said.

"[But] the Crown will not take his plea to manslaughter, they want him for murder and so here we are to fight over which it is."

Of the Crown's 21 witnesses set to give evidence, Patricia was the first to be called and will continue on Tuesday.

The retrial, before Justice Helen Cull, is estimated to take two weeks.