The Christchurch gunman is seeking to appeal his convictions and withdraw his initial guilty plea. Brenton Tarrant, an Australian white supremacist, has asked the New Zealand High Court to set aside his guilty pleas for the 2019 murders of 51 people.

The court must first decide whether his appeal can go forward, since it was filed after the official deadline. Judges will also examine whether his conditions in prison made him unable to think clearly or make rational decisions at the time he pleaded guilty.

If the court grants his application, the case will return for a new trial. If the judges deny the request, his appeal against his sentence will be heard at a later date. Security has been tightened for the hearing, a process that many victims and their families find deeply painful.