A man charged with murdering his cellmate at Manawatū Prison near Palmerston North has been found unfit to stand trial.
Justice Cheryl Gwyn ruled the man was mentally impaired, but reserved her decision on whether he killed Bradley King in February last year.
Even if she found the man responsible for the death, he won't be convicted of murder because of his mental state.
The man, whose name is suppressed, was excused from attending a hearing in the High Court at Palmerston North on Wednesday.
The judge's decision that the man won't face trial came after two expert reports into his mental health.
King, a 36-year-old from Palmerston North, was assaulted on 11 February, 2021, and died of his injuries in Wellington Hospital 13 days later.
He was in custody, having been denied bail for burglary charges, and was double-bunked with the man accused of his death.
"It was clear from the circumstances in which the alleged offending occurred that there was a disordered or disturbed mind at play for [the accused] at that stage," Crown prosecutor Ben Vanderkolk told the court.
Defence lawyer Nicola Graham said how King and the man ended up in a cell together would likely be examined at a coronial inquest.
The lawyers agreed evidence suggested the man was responsible for King's death.
"There were two people in the cell, nobody else," Graham said. "This is a case that is actually very straightforward in that regard."
Vanderkolk said three statements from prisoners in nearby cells described noises consistent with a "prolonged and violent attack".
In an interview with police the accused made admissions about how King was injured.
Vanderkolk said those injuries led to King's "tragic death".
Members of King's family were in court, but Graham said the accused's family decided not to attend.
Although they wished to meet King's family, they didn't think a courtroom was an appropriate setting for that first encounter, she said.
After Justice Gwyn has issued her decision there will be a further hearing to decide what will happen to the accused.