Brenton Harrison Tarrant, 28, has been charged with murder in relation to the massacre on Friday, in which 49 people were killed and 42 injured.
Handcuffed and wearing a white prison suit, Tarrant did not speak.
Two other armed suspects were taken into custody Friday while police tried to determine what role, if any, they played in the cold-blooded attack that stunned New Zealand, a country so peaceful that police officers rarely carry guns.
'Just 24 hours after the Christchurch shooting New Zealand bans semiautomatic guns!' she wrote in reference to New Zealand Attorney General David Parker's comments about banning the controversial weapons.
The attack is the worst shooting in the country's history and has seen its threat level raised to high for the first time. After investigations, Mr Bush said the woman had been released without charge.
From time to time people outside the cordon came to place flowers under a tree to express their condolences to the victims. He is likely to face more before his next appearance on April 5.
Most of the dead were killed at the Masjid Al Noor mosque on Deans Avenue, before gunfire broke out at Linwood Masjid six kilometres away.
New Zealand police said 49 people were killed and 42 were being treated for wounds, including a four-year-old child.
Hungry for any news, families and friends of the victims gathered at the city's Hagley College, near the hospital. She also says New Zealand will make "weekly compensation" available to victims' dependents on an ongoing basis.
Barefoot, handcuffed: New Zealand mosque shooter smirks, flashes ‘white power’ sign in Christchurch court
Prior to the shooting, Tarrant had no previous criminal record in either Australia or New Zealand and "was not known to authorities in connection with far-right violence", according to Ardern.
'Those decisions have yet to be taken, ' he told Radio New Zealand.
"I still don't know where he is", she said.
New Zealand citizens as young as 16, provided they pass a background check to get a firearms license, can possess a long gun.
"I can tell you one thing right now, our gun laws will change", Ardern said adding that a ban on semi-automatic weapons would be considered.
Ardern said the main suspect was a licensed gun owner who used five weapons during his rampage, including two semi-automatic weapons and two shotguns. Residents were mandated to turn in their semi-automatic rifles and other now-outlawed weapons.
Ardern called on the US government to show "sympathy and love for all Muslim communities", and told the press that "the person who has committed this violent act has no place here".
A host of world leaders, including US President Donald Trump and UK Prime Minister Theresa May, expressed sorrow and disgust at the attacks.More news: Eggs are bad again? New study raises cholesterol questions
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