They want to know if there were any signs.
If anything could have been done to prevent this unspeakable tragedy. How he went undetected by authorities.
As one neighbour told us: "It makes me sick. Now every time I look out the kitchen window I think, how many guns? How many bombs did he have in there?"
It is the job of journalists to engage in the challenging.
The alleged gunman is part of this story and we can't shy away from that.
It doesn't give his abhorrent views a platform.
He may not have applied to have his name suppressed, but Judge Paul Kellar denied him notoriety when he ordered his face be pixelated in any photos taken as he stood in the dock the day after he allegedly gunned down dozens of people, killing 50.
Prime Minister Jacinda Ardern has said she will never speak his name.
Our piece keeps the mentions of his name to a minimum.
The extent to which we refer to the manifesto and livestream video has also been kept to a minimum but they are important to build a picture of his motivations and are placed in context with academic criticism.
We sought out experts who study extremism and its motivations, neighbours, the gun club he was a member of and the Islamic Women's Council.
If the information can in any way equip authorities and experts in being alert to people with these types of ideologies — and help the public be wary — we have done our job.