New Zealand police chief Mike Bush said the man was scheduled to appear in a court in Christchurch on Saturday
. CNN did not confirm that this was his real name. This is the name he called himself online. The New Zealand police did not publicly identify the gunman.
Bush said he knew a name was circulating in the media, but it would be inappropriate to confirm it.
Two others were arrested with firearms. The police try to verify their involvement. The New Zealand authorities claim that they had no prior information on the persons arrested.
A number of weapons were found at the scene of the shooting. According to Bush, two improvised explosive devices were attached to a vehicle as part of the attack.
The attack was posted on Facebook
A video of 17 minutes shared on social networks claims to show some of the attack.
The sequence, which seems to have been taken with a helmet camera, shows a man riding in the streets of Christchurch. The camera shows several weapons on the passenger side of the vehicle.
The song "Remove Kebab", an anti-Muslim anthem that pays tribute to a Bosnian Serb leader convicted of genocide, plays in stereo while he drives.
He can be seen using a GPS to get to the Masjid al Noor Mosque, where he opens fire on worshipers during a horrific attack.
Police said they knew about the video. They asked social network users to stop sharing graphic sequences, broadcast live on Facebook.
"The New Zealand police alerted us to a video on Facebook soon after the live stream started and we removed the shooter's Facebook account and video. We also remove any praise or support for the crime and the shooter or shooters as soon as we know about it, "said a spokeswoman for Facebook New Zealand, Mia Garlick, in a statement.