Tyler Robinson allegedly made comments about Charlie Kirk's assassination on Discord after the shooting, a roommate has told investigators.
Kirk, 31, was assassinated while speaking at a Turning Point USA event at Utah Valley University on Thursday.
The alleged assassin was identified by US authorities as 22-year-old Robinson late on Friday after he eluded police and federal agents for more than 30 hours after the shooting, in which a sniper fired a single gunshot.
His own family handed him in, and a family member reached out to a family friend who contacted the Washington County sheriff's office, according to Utah Governor Spencer Cox.
Previously, investigators said they had found the bolt-action rifle believed to have been used to kill Kirk and released images of a person of interest