New York Attorney General Letitia James Wednesday stated that the New York Department of Law launched an investigation into several social media platforms they believe a shooter responsible for killing 10 people at a Buffalo supermarket used to plan, promote and stream the attack.

The shooting occurred May 14 when 18-year-old Payton Gendron committed what the FBI has called an act of “racially motivated violent extremism.” Gendron drove to a Buffalo supermarket and shot 13 people, leaving 10 dead. The neighborhood in Buffalo where the shooting occurred is a predominately African-American neighborhood.

In a tweet, James stated that her office would investigate the video live streaming service owned by Amazon called Twitch, online message boards 4chan and 8chan, internet chat site Discord, and other platforms.

James explained, “This terror attack again revealed the depths and dangers of these platforms that spread and promote hate without consequence. We are doing everything in our power to stop this dangerous behavior now and ensure it never happens again.”

Authorities have said that Gendron broadcasted the attack in real-time on Twitch and was believed to have released a 180-page white supremacist manifesto and an account of his preparations for the shooting on social media prior to the attack.

Gendron has pleaded not guilty to the attack and has been jailed without bail on a charge of first-degree murder.