The man charged over Friday's twin mosque attacks in the New Zealand city of Christchurch is believed to have acted alone, police say.
Australian Brenton Tarrant, 28, a self-described white supremacist, live-streamed the attack on Facebook.
Three others arrested afterwards are not believed to have been involved, Police Commissioner Mike Bush said.
Tributes have been paid for the 50 victims while the first bodies are expected to be released for burial.
About 34 people are in hospital receiving treatment for injuries including severe gunshot wounds. A four-year-old girl remains in a critical condition.
Bodies to be returned by Wednesday
New Zealand Prime Minister Jacinda Ardern said her cabinet would discuss issues including gun policy reform on Monday, repeating that there would be "changes to our gun laws".
Speaking to reporters on Sunday, she said parliament on Tuesday would pay tribute to victims of what she described as an "act of terror" and that she expected the bodies of all those killed to be returned to their families by Wednesday.
Ms Ardern also said there were "further questions to be answered" about the role of social media sites such as Facebook, which was used to broadcast live footage of the attacks. She said these platforms had "a wide reach" and this was "a problem that goes way beyond New Zealand".
Facebook said it had removed as many as 1.5 million videos of the attack from its site in the first 24 hours and that "all edited versions of the video that do not show graphic content" were also being deleted.
Ms Ardern confirmed that her office had received a document from the suspect nine minutes before the attacks but that it did not contain any specific details, such as a location. She said it was forwarded to the security services within two minutes.
Separately, Commissioner Bush said authorities were working as fast as they could to finish formally identifying the victims of the attacks at the Al Noor and Linwood mosques. It was a sensitive process and that he was "aware of the cultural and religious needs".
'No-one else involved'
The main suspect appeared in court on Saturday in a white prison shirt and handcuffs, smiling for the cameras. He has been charged with one count of murder with more charges expected to follow.
Mr Tarrant had a firearms licence and owned five guns, Ms Ardern said. He did not have a criminal record and had not been on the radar of security services in New Zealand or Australia.
The suspect was the only person charged with carrying out the shootings, Commissioner Bush told reporters. He also said:
# Police did not believe that three other people arrested were involved but he said he could not be conclusive
# A man was charged with firearms offences while an 18-year-old would appear in court on Monday
# A woman was released without charge
Mr Tarrant has been remanded in custody without a plea and is due in court again on 5 April. The presiding judge ruled that the suspect's face should be pixellated in photographs and moving images to preserve his fair trial rights.
Brother 'proud' of hero victim
Two of the nine Pakistanis killed - Naeem Rashid, 50, and his 21-year-old son Talha - had been living in New Zealand since 2010.
Mr Rashid has been hailed as a hero on social media after being seen in a video of the attacks apparently trying to tackle the gunman at Al Noor mosque before being shot, BBC reports.
His brother Khursheed Alam in the northern Pakistani city of Abbottabad said he was "a brave person".
"There were a few witnesses who said he saved a few lives by trying to stop that guy," he said. "It's our pride now, but still the loss - it's like cutting your limb off really."
At the Linwood mosque, Abdul Aziz said he had run towards the gunman outside the mosque, throwing a credit card machine at him.
In the ensuing chase, the gunman dropped one of his weapons and went to fetch more from his car, when Mr Aziz tossed the gun towards him, smashing the car window.
The gunman then drove off and was arrested moments later.
Officials in New Zealand have shared a list of victims with families, but not released it publicly. Some of the other known victims are:
# Sayyad Milne, 14, who wanted to be a footballer when he grew up
# Daoud Nabi, 71, who is believed to have thrown himself in front of other people in the mosque to protect them
# Khaled Mustafa, a refugee from the war in Syria
# Hosne Ara, 42, killed while searching for her husband who uses a wheelchair - he survived