New Zealand mosque shooter tells court mental health forced him to plead guilty

• Did not have "mental health" required to make decisions: Tarrant.
• Tarrant opened fire on two mosques during Friday prayers.
• Convict serving life sentence in prison without parole.

A white supremacist who killed 51 Muslim worshippers at two mosques in New Zealand seven years ago said on Monday that he was irrational when he pleaded guilty, local media reported, as he sought to overturn his conviction in a New Zealand court.

Brenton Tarrant, 35, who appeared in a court in Wellington via a video link, is seeking to appeal his guilty pleas.

Tarrant, an Australian national, opened fire on two mosques in Christchurch in March 2019 during Friday prayers in the deadliest mass shooting in New Zealand's history.

He released a racist manifesto shortly before the attack, where he used military-style semi-automatic weapons and livestreamed the killings on Facebook with a head-mounted camera.

Tarrant initially denied all charges and was preparing to stand trial after the attack but entered guilty pleas a year later to 51 charges of murder, 40 counts of attempted murder and one charge of committing a terrorist act.

Tarrant told the court that harsh prison conditions had deteriorated his mental health while awaiting trial, and that he was essentially not fit to plead guilty, according to a report in the New Zealand Herald.

"I did not have the mind frame or mental health required to be making informed decisions at that time," Tarrant said.

"I think the issue is, did I really know what I wanted to do or what would be a good idea? No, I didn't actually ... I was making choices, but they were not choices made voluntarily and they were not choices made rationally due to the (prison) conditions."

Counsel acting for Tarrant have their names and identities suppressed by order of the Court and could not be reached for comment.

A court document showed the Court of Appeal would check if Tarrant was incapable of making rational decisions when he entered his guilty pleas "as a result of the conditions of his imprisonment, which he says were torturous and inhumane".

He is serving a life sentence in prison without parole — the first time a New Zealand court imposed a sentence requiring a person to spend the rest of their life in prison.

The appeal hearing is set down for five days, and is expected to finish on Friday.

If the appeal court declines to grant the application to vacate the guilty pleas, a hearing later in the year will consider the appeal on his sentence. If the appeal is accepted, the case will be sent back to the High Court for Tarrant to stand trial on the charges.