The unsurpassed mass plays were carefully planned and have shocked the usually peaceful nation
New Zealand Prime Minister Jacinda Ardern described the attack as one of the country's "darkest days". She said the suspects had "extremist views" that have no place in New Zealand or anywhere else in the world.
An Australian citizen in his late 20s has been charged with murder in connection with the attacks. Two other people were arrested just after the Scots.
This is what we feel so long.
When the Christchurch Scots happened
A gunman directed two mosques in downtown Christchurch at lunchtime Friday local time. Friday is the liveliest day for many mosques around the world.
The first and most deadly shot took place shortly after 1
A graphic video streaming live on social media for about 17 minutes turns out to show some of the attack: In it is seen a man running through the streets of Christchurch before coming to the mosque and eventually opening fire.
The horrific attack on the al Noor mosque, including the time when the shooter returns to
When the shooter drove away from the al Noor mosque, he opened fire on several people walking along the street. The video looks to show.
Shortly after the live stream, a second attack ended at the Linwood Mosque. At least seven people were killed there and another died later in the hospital.
A number of weapons were recovered at both sites. Ardern said that improvised explosive devices were also in place.
What we know about the suspects
He appeared in Christchurch District Court on Saturday. Under his short appearance, Tarrant was handcuffed and accompanied by three officers armed with tasers. He was silent in the appearance of his judge and was released in custody to return to court on April 5.
Just before the Scots, a link to an 87-page manifest on Twitter and 8chan, an online message card used by anonymous accounts to share extremist messages and cheers on shooters, was posted to an account in Tarrant's name  The Manifesto is unsigned. Its author claims he is a 28-year-old white man, born in Australia. It is filled with immigrants and anti-Muslim feelings, as well as explanations for an attack.
Tarrant has traveled around the world, "with sporadic periods of time in New Zealand," Ardern said at a press conference. She added that he was based in Dunedin, New Zealand during the attack.
She told reporters that none of the people who had been arrested, including Tarrant, had been on some watch lists.
New Zealand's gun control laws were reviewed
Prime Minister Ardern announced early Saturday's local time that New Zealand's arms laws would change in response to the terrorist attack.
She said the chief offender had a pistol license and used five pistols during the attack – including two semi-automatic weapons and two shotguns.
"While work is being done against the chain of events leading to both possession of this gun license and possession of these weapons, I can tell one thing right now. Our arms laws will change," she told a press conference in Wellington.
CNN's Eliza Mackintosh and Gianluca Mezzofiore contributed to this story.