The lawyers have throughout the hearing presented a number of independent assessments of the unit the gunman was held in at Auckland Prison to support their case.
These included the “Nelson Mandela Rules”, which were adopted by the United Nations in 2015 and govern the minimum standard for prisoners.
The rules were named in honour of Mandela, who advocated for the fair and humane treatment of all, including prisoners, after spending 27 years in custody.
This week, Tarrant and his lawyers have been in the senior court, seeking leave to appeal against his convictions and to vacate his guilty pleas for the mass shootings at two Christchurch mosques on March 15, 2019.
He was jailed for life without parole in 2020 for murdering 51 people at the Al Noor and Linwood mosques.
The Christchurch mosque gunman gave evidence at the Court of Appeal on Monday. Photo / Ministry of Justice
The crux of his claim is that the harsh prison conditions he was subjected to while awaiting trial severely impacted his mental health and meant he was effectively “forced” to change his plea to guilty.
“If I had another option, I would have taken it,” he told the court while giving evidence by audiovisual link earlier this week.
His legal team maintains that the claimed inhumane conditions meant he couldn’t adequately prepare his defence case.
They say Tarrant’s pleas were influenced by oppression to such an extent that they weren’t freely given.
Central to their case is the conditions at the prison where the gunman has been held following his arrest.
Details of the conditions under which he was kept have been given in court this week, including being held in severe social isolation for over a year, while also under constant video surveillance.
He was also subject to 15-minute checks by staff that ran around the clock, which involved opening the flap in his cell door every 15 minutes. At night, a torch was shone in.
Counsel A told the court there was no question their client suffered from sleep deprivation, estimating a light had been shone in his cell 17500 times, while he’s been in custody.
“It’s ridiculous to suggest that this wouldn’t have an impact on his sleep,” they said.
Contact with staff was kept to a minimum, to the point it was described as transactional. There were many hours when he sat in his cell with nothing to do.
“The conditions in which he was kept are incomparable to any other inmate in the modern history of the Department of Corrections,” his second lawyer told the court.
They argue that as a result of these conditions, the gunman felt unable to make rational choices, retain “mental equilibrium” or engage in the judicial process in a logical, consistent and appropriate manner.
Counsel A pointed to the indication he gave his lawyers of a desire to plead guilty, only to change his mind a couple of days later, as evidence of his fluctuating mental health.
“His rational position was he wanted to go to trial, but he had been so psychologically eroded that it affected his sense of self,” Counsel A told the court.
Asked by Justice Christine French how his claim that he wanted to defend the charges squared with the conflicting evidence of two of his former lawyers that the gunman had always indicated that he intended to plead guilty, Counsel A said that was a disputed fact and Tarrant maintained he was going to defend himself.
He had been assessed as being “at risk” for the past five-and-a-half years, but argued this was simply an excuse to deprive him of his basic needs and resulted in him being held in conditions which he described as “torturous and inhumane”.
Over the course of the week’s hearing, the court has heard evidence about the impact on his mental health, including how he was assessed and found fit to plead following his arrest.
Counsel A told the court that the conventional “fit to plead” assessment didn’t fit this case, because its circumstances were so unique that it wouldn’t be caught by the conventional test.
The lawyer concluded their remarks to the judges by inviting the court to allow the appeal, saying Tarrant’s pleas weren’t voluntarily given and had been recorded after their client was housed in some of the most oppressive conditions that existed in New Zealand.
They urged the court to believe Tarrant’s account, saying it was supported by specialist reports, academic articles and those from independent watchdogs.
Tomorrow, the Crown will make its submissions.
Catherine Hutton is an Open Justice reporter, based in Wellington. She has worked as a journalist at the Waikato Times and RNZ. Most recently she was working as a media adviser at the Ministry of Justice.