Officials said the gunman broadcast the attack live on Twitch, the livestreaming site owned by Amazon that is popular with gamers.
Twitch said it had taken the channel offline within two minutes of the violence starting. The channel’s page said only that it was “currently unavailable due to a violation of Twitch’s community guidelines or terms of service.”
In a statement, a Twitch spokeswoman said the site “has a zero-tolerance policy against violence of any kind and works swiftly to respond to all incidents. The user has been indefinitely suspended from our service, and we are taking all appropriate action, including monitoring for any accounts rebroadcasting this content. ”
Screenshots of the broadcast were circulating online, including some that appeared to show the shooter holding a gun and standing over a body in the grocery store.
In a manifesto posted on the forum 4chan, the shooter wrote that he would use a GoPro Hero 7 Black camera to “livestream the attack on Twitch,” which he chose so “all people with the internet could watch and record.” He noted that the shooting at a Jewish synagogue in Halle, Germany, in 2019 was also livestreamed on Twitch.
Other social media posts showed what was said to be a list of instructions the shooter had made for himself – a to-do list that included “continue writing manifesto” and “test livestream function before the actual attack” – on the messaging platform Discord. The Discord user name matched the name of the Twitch channel.
Discord has taken steps to improve its content moderation in recent years – especially after white supremacists used the site to plan the “Unite the Right” rally in Charlottesville, Va., In 2017. But it still relies heavily on user reports, particularly in private servers that are invite-only and less visible externally.
Discord said it was investigating the postings, which had been made in a private server, and was working with law enforcement officials but would not comment further.
“We extend our deepest sympathies to the victims and their families, and we will do everything we can to assist law enforcement in the investigation,” the company said.