The sentencing of the white supremacist gunman who killed 51 worshippers in a New Zealand mosque last March is due to begin this week in Christchurch’s High Court.

He initially pleaded not guilty to 51 counts of murder and 40 counts of attempted murder, but changed his plea to guilty earlier this year.

New Zealand Prime Minister Jacinda Ardern described the incident as “one of New Zealand’s darkest days” and initiated hard restrictions on gun ownership in the country, as well as leading a global campaign against online extremist content.