Christchurch shooter smirks in court
The Australian stood silently during the brief hearing as he was charged with one count of murder. He was remanded in custody without plea and is due to appear in court on April 5.
Judge Paul Kellar did not reveal the victim's name on grounds of undue hardship to his family.
Two other people were in custody over the incident. None of those detained had a criminal record.
After Tarrant left the court, Judge Kellar said that while "there was one charge of murder brought at the moment, it was reasonable to assume that there will be others".
Speaking at a news conference on Saturday, Prime Minister Jacinda Ardern said the suspect's car was full of weapons, suggesting "his intention to continue with his attack".
He had obtained a gun licence in November 2017 that allowed him to buy the weapons used in the attack. Ardern said that the guns appeared to have been modified.
"The mere fact... that this individual had acquired a gun licence and acquired weapons of that range, then obviously I think people will be seeking change, and I'm committing to that," she said.
New Zealand's Attorney-General David Parker said the government would look into banning semi-automatic weapons, but that no final decision had been made.
Tarrant, who grew up in the Australian town of Grafton, had been living in the Dunedin, about 360 km south of Christchurch.
The Australian police were investigating Tarrant's connections around Grafton. Before his appearance at the court, New Zealand Police Commissioner Mike Bush said Tarrant had been charged with one count of murder, with other charges to follow.
Tarrant was one of three people arrested in connection with the shootings at the Al Noor Mosque and the Linwood Avenue Masjid. The other two remain in custody but their role in the shootings was unclear, CNN said.
A fourth person who had been taken into custody was later determined to be an armed bystander who wanted help police.
Ardern, while speaking at the Christchurch Canterbury Refugee Centre on Saturday, said bodies were still being removed from the Al Noor mosque - the site of the first attack.
She added that financial support would be made available to those who had lost someone on whom they were financially dependent.
A total of 48 people were wounded in the shootings.
India, Bangladesh and Indonesia all say some of their citizens were killed in the shooting and others are unaccounted for.
Friday's killing was a terrorist attack that appeared orchestrated for the social media. The brutal shootings were previewed on an infamous Internet message board and then graphically live-streamed on Facebook.
An 87-page manifesto, found by authorities after it was posted online, was filled with anti-immigrant and anti-Muslim ideas.
According to the latest census figures, Muslims make up about 1.1 per cent of New Zealand's population of 4.25 million. Numbers rose sharply as New Zealand took in refugees from various war-torn countries since the 1990s.