The alleged shooter appeared in court amid strict security, shackled and wearing all-white prison garb, and showed no emotion when the judge read him one murder charge.
"We think also of our Cook Islands community in Christchurch and in New Zealand, with so many of our people who have made their homes there".
Background checks can not stop a determined attacker because these checks look backward; they search for past crimes and problems. "Our investigations are in their early stages and we will be looking closely to build a picture of any of the individuals involved and all of their activities prior to this horrific event", Police Commissioner Mike Bush said.
"It was his intention to continue his attack", the prime minister said. "Clearly what has happened here is an extraordinary and unprecedented act of violence", she added.
Ardern said the suspect was a licensed gun owner who bought the five guns used in the crimes legally.
On Monday, government officials plan to hold a cabinet meeting which will "focus on the ease with which legal weapons can be modified to become military-style assault rifles, which are more strictly controlled".
Prime Minister Jacinda Ardern, after meeting families of Christchurchterror attacks' victims, says the country stands united and grief and that their gun laws will change in the aftermath of the attack on Christchurch mosques.
A gunman opened fire on worshippers in two mosques in Christchurch, killing 49 people.
Dozens of people laid flowers at cordons near both mosques in Christchurch, which is still rebuilding after an natural disaster in 2011 killed nearly 200 people.
The video footage showed a man driving to the mosque, entering it and shooting randomly at people present inside.
The gunman had posted a jumbled, 74-page manifesto on social media in which he identified himself as an Australian and white supremacist who was out to avenge attacks in Europe perpetrated by Muslims.
Ardern noted that this individual traveled around the world and spent "sporadic periods of time" in New Zealand.
A self-described "ethno-nationalist", Tarrant worked as a personal trainer from 2009 to 2011 before beginning the first of many trips across the globe. Tarrant did not apply for bail, and per ABC Newsreports, did not apply to have his name suppressed.
Most of the victims of the attacks were immigrants from Pakistan, India, Malaysia, Indonesia, Turkey, Somalia and Afghanistan.
"Unfortunately, we are all too familiar with the devastating effect a mass shooting has on a faith community", said Meryl Ainsman, chair of the board of the Jewish Federation of Greater Pittsburgh.