To put that into grisly context, that's worse than any mass shooting in the US, bar one.
The gunman's attack was choreographed for Facebook Live. He was able to livestream for 17 minutes. And in the hour or so that it took Facebook to take the video down, around 4000 saw the clip - some of whom copied it.
So it was already spreading across the internet like wildfire by the time that Facebook - whose AI systems had failed - responded to a complaint from the NZ Police.
It would be good if Facebook founder emerged to explain how his company will prevent its platform being abused in future, or to look into the faces of victim's families and explain why not.
If it had happened in America, Zuckerberg would be talking.
Why is New Zealand any different?
To be cynical, it's because our politician have less ability to influence the way Facebook's is regulated, or harm its bottom line.
Change is possible. In the US, legal pressure has just seen Facebook introduce a major overhaul of its lucrative targetted ad system.
And as one of my colleagues noted, a new law in Germany defines Facebook as a publisher and threatens it with fines of up to 50 million Euros ($80m) if it hosts hate speech. That's focused the social network's attention on eliminating the kind of hate speech that ultimately fosters violence (NZ hate groups continue to operate on Facebook, though inhouse guidelines prevent images they've posted being published with this article, despite still being live on the social network).
Here, we have recently gone in the opposite direction, with our lawmakers hosing down a request by Privacy Commissioner John Edwards - who has been constantly grappling with Facebook, including over the Christchurch killings - to impose fines of up to $1m on recalcitrant companies.
Yesterday, Facebook did make its top content cop available to the Herald for an interview.
"This has obviously been a horrific tragedy and it is something that has been weighing on all of our hearts," VP for Global Policy Monika Bickert said.
"I want to emphasise that our hearts go out to the victims families and everything that's happened.And I know that the images in the video are very disturbing. And I say that with first-hand knowledge because as part of my job I had to watch the video and it was incredibly difficult."
Earlier, in anger, I raised questions about Facebook's seeming commercial motivation to maintain Facebook Live and, at the end of the day, not budge an inch.
And the Washington Postwrote, "Friday's uncontrolled spread of horrific videos - a propaganda coup for those espousing hateful ideologies - also raised questions about whether social media can be made safer without undermining business models that rely on the speed and volume of content uploaded by users worldwide."
Bickert said it wasn't as simple as suspending Facebook Live. The offending video was shared through many different mechanisms on the social network.
She also made a public safety argument for keeping Facebook Live and other video sharing features on while authorities and ISPs - and Facebook itself - struggled to block all instances of the massacre clip.
People can use Facebook Live to communicate during emergencies, Bickert said.
She also said that over the past year, there had been around 3500 instances of people threatening self-harm or suicide on Facebook services including Facebook Live. Facebook AIs had been able to detect the activity and the company was able to alert first responders.
The person at the top should be making them if he wants to stop Justice Minister Andrew Little pusing Five Eyes to clamp down on social media, Aussie PM Scott Morrison doing the same with the G20, more Kiwi companies pulling ads or funds with $90 billion under-management dumping shares.
The Herald and its NZME stablemate NewstalkZB have both requested interviews with Zuckerberg.