Wearing a white prison suit, Tarrant appeared handcuffed and barefoot.
Witness Len Peneha said he saw a man dressed in black enter the mosque and then heard dozens of shots, followed by people running from the mosque in terror.
He now remains in custody, remanded after a brief court appearance at Christchurch district court on Saturday.
One person died in Christchurch hospital last night and staff are treating 42 patients, ranging from young children to adults, with gunshot wounds. Facebook, Twitter and YouTube all said they had taken steps to remove copies of the videos.
For many, the road to recovery will require multiple surgical procedures and many survivors said the mental scars may never fully heal.
Of the four people police apprehended on Friday, one was released ― an innocent bystander who "was just trying to get their kids home", Bush said.
"It's outrageous" he said.
The victims of Friday's shooting included immigrants from Jordan, Saudi Arabia, Turkey, Indonesia, and Malaysia.
The worshippers and their families caught up in the attacks in the normally peaceful city of Christchurch came from around the world. "And those values, I can assure you, will not, and cannot, be shaken by this attack". "Our hearts are breaking for your loss", read one of the notes marked with a string of x-kisses.
New Zealand Rugby spokesman Nigel Cass said the decision to cancel Saturday's game in Dunedin was made after an urgent meeting involving both teams, venue management and police. The minimum legal age to own a gun in New Zealand is 16, or 18 for military-style semi-automatic weapons.
"I can tell you one thing right now, our gun laws will change, " Ardern said.
Meanwhile, outside the court, major roads in the city center are cordoned off with heavy armed police officers on duty.
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Another of Daoud´s sons, Yama, was on the way to the mosque - to make up with his father after a small falling out - when he bumped into a friend outside who told him "your father saved my life".
Tarrant is expected to face additional charges and two others are in custody.
"Charges have been laid, we can expect additional charges will be appearing in the high court on the fifth of April, so there is obviously a process that needs to be gone through here", she said.
"I'm also in the same building as the people bringing him to justice", she said.
Numerous victims hailed from around the world.
[I came], frankly, to stand with those people who believe that we can not just any longer just talk about Islamophobia and hate.
Australian Prime Minister Scott Morrison confirmed that one of the people detained was an Australian-born citizen.
A pair of rural New Zealand police officers dramatically arrested the suspected Christchurch gunman 36 minutes after authorities were alerted, it emerged Saturday, as the prime minister hailed their bravery.
The attack has prompted searching questions about whether right-wing extremism has been treated with enough seriousness by Western governments.
Ali Soufan, a former high-ranking Federal Bureau of Investigation counter-terrorism agent, said the threat needs to be treated with the same seriousness as jihadist violence.
Authorities have not specified who they detained, but said none had been on any watch list.
"It is clear that this can now only be described as a terrorist attack", Ardern said. He had no criminal history in New Zealand or Australia and had not drawn the attention of the intelligence community for extremist views.
"I have asked our agencies this morning to work swiftly on assessing whether there was any activity on social media or otherwise, that should have triggered a response".