Brenton Tarrant, 28, from Australia, appeared in court in Christchurch charged with one count of murder, however New Zealand Police said further charges were expected to follow.
"There is one charge of murder brought at the moment, it is reasonable to assume that there will be others", said the judge, whose name was not reported by the AP.
In response to the attacks, New Zealand Prime Minister Jacinda Ardern described the massacre as a "terrorist attack" at a news conference, saying: "These are people who I would describe as having extremist views that have absolutely no place in New Zealand and in fact have no place in the world".
Tarrant has been described as a suspected white supremacist, based on his social media activity. Worshippers, possibly dead or wounded, lay on the floor, the video showed. He was ordered to return to court again April 5.
The gunman then walks back into the mosque, where there are at least two dozen people lying on the ground.
Officials say forty-one people died at the Al Noor Mosque, and seven were killed at the Linwood Mosque, a 10-minute drive away. No images have emerged from the second mosque. He said he was not a member of any organization, but had donated to and interacted with many nationalist groups, though he acted alone and no group ordered the attack.
"They were rural community cops I understand from Lincoln (a nearby town) who were present here".
A fourth person who had been taken into custody was later determined to be an armed bystander who wanted to help police.
Mr Sayed, who has been living in New Zealand for over 10 years, told Indian broadcaster NDTV that he had witnessed the man "creep up behind the shooter and hold him until his gun dropped".
Roberson said a 4-year-old girl who has been transferred to an Auckland hospital in critical condition and 11 patients who remain in Christchurch are also critically wounded.
The London Ambulance Service were also called but the 27-year-old victim was driven directly to an east London hospital by friends.
"My kids are scared, you know".
Friday prayers at the Windsor Mosque on March 15, 2019, a day after a gunman killed 49 people at two mosques in Christchurch, New Zealand.
"The regulation of guns in New Zealand is categorised as restrictive", say the authors of the database.
Ardern said the victims came from across the Muslim world, with Turkey, Bangladesh, Indonesia and Malaysia among the countries rendering consular assistance. "I'm not sure how to deal with this". Nabi's family left Kabul, Afghanistan, for New Zealand in the 1970s.
"I can't. believe that somebody I've probably had daily dealings with and had shared conversations and interacted with would be capable of something this extreme", Gray told Nine Network television.
"He was professional, he was punctual, reliable.as normal as one person to the next", she said.
Rules in New Zealand require gun owners to be licensed, but unlike neighboring Australia, laws do not require all weapons to be registered, giving authorities poor oversight of the country's firearms, according to GunPolicy.org.
The New Zealand premier was showered with vast praises internationally for the gesture, which made it clear that New Zealand stood by the Muslim community that was the centre of Friday's horrifying terror attacks rooted in racial as well as religious hatred. The AR-15 is a semi-automatic version of the United States military M16 rifle. The alleged gunman obtained a gun license in November 2017.
Several guns have been recovered from both mosques, while, two explosive devices were found on two vehicles at the scene, one of which was defused, the police confirmed. Versions of the video reportedly persisted on the sites for hours after the shootings.
Christchurch residents including the Muslim community are mourning the victims of the attacks.
I felt the need to come out and stand in solidarity with people who were remembering the people who were killed and injured in New Zealand; to stand with my community, the Muslim community, at a time when we feel very vulnerable - when we feel like we've been punched in the gut in a big way. The invaders, he said, would never be able to "replace" "our people".
"They are assisting to repatriate them (families) with their loved ones in a way that is consistent with Muslim faith while taking into account these unprecedented circumstances and the obligations to the coroner", Ms Ardern said.
Political and Islamic leaders across Asia expressed their disgust at the deadly shooting. I am just posting this video to show that I am OK. "1.3 billion Muslims have collectively been blamed for any act of terror".