An update...
We are now up to 50 deaths, an extra body that had others on top of it was discovered after police started removing bodies. There are 50 people in hospital, 36 with series injuries, 2 who are critical. There are children as young as 3 in 4 in hospital that have been shot. Police have not released a list of the victims yet, there is an unofficial list so that families can confirm the deaths of loved ones. There are children among the dead.
It was a single gunman, other arrests during the crisis were unrelated. The gunman had 5 guns, 2 semi-autos, 1 lever action, and 2 shotguns. There were also explosives recovered in his vehicle. The gunman had no criminal history. He is an Australian, who has been in and out of NZ over the last couple of years. According to his manifesto he came to NZ to train for an attack he was going to carry out in Australia, but for unknown reasons decided to do it here.
The two cops that captured him committed an extreme act of bravery (imho), they deduced he was likely going to a 3rd location (my guess is that was a 3 mosque in the north of the city) - rammed his vehicle on the driver side door - he may have received a rifle butt to the face to encourage co-operation. In the arrest video it looks like he popped his rear door open possibly intending to grab a gun from the back.
It sounds like he made a lot of money in the Bitconnect ponzi scheme. This funded his travels, vehicles, and firearms.
In NZ we do not have the death penalty, and a life sentence is not really life. But we do have a preventative detention law, which will be used assuming he is not evaluated as insane.