The 18-year-old man charged in the deadly mass shooting in Buffalo, New York, invited people to a Discord chat room to see his plans about 30 minutes before carrying out the attack, the New York Times reported Tuesday. citing the messaging application.

Eleven of the 13 people shot were black. Ten of the victims were killed in the shooting, which the gunman broadcast live on a social media platform.

In the months leading up to the attack, Gendron posted his attack plans in a private Discord chat room that only he could see, the New York Times and other outlets reported. The posts included hand-drawn maps of Tops Friendly Market, where the attack took place. “What we know at this point is that the suspect created a private, invite-only server that served as a personal journal chat log,” Discord said.

“Approximately 30 minutes before the attack, however, a small group of people were invited and joined the server. Prior to that, our records indicate that no other person viewed the diary chat on this private server,” Discord added.

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