New York state’s governor says tech firms have questions to answer to and even share some blame for the attack.
The inquiry will examine how social platforms were used to “stream, promote, or plan” the event.
The suspect is accused of killing 10 people in a supermarket located in a predominantly black neighbourhood in Buffalo.
Police allege he posted a manifesto on Google and livestreamed the whole event.
Attorney General Letita James says the terror incident has once again revealed the depths and danger of online forums spreading hate.
The stream was taken down by Twitch within two minutes of the shooting beginning, but has been duplicated and shared on other platforms.
