Omar Mateen, who authorities say killed 49 people at the gay nightclub Pulse in Orlando, Fla., was reportedly no stranger to the club.
Multiple media outlets are reporting that some Pulse regulars recognized Mateen, saying that he had spent time at the nightclub before the shooting early Sunday. Witnesses have said the same to authorities, NPR's Dina Temple-Raston reports, citing U.S. officials with knowledge of the investigation.
Meanwhile, at least two men have told the media they interacted with Mateen on gay dating apps. Investigators have not commented on the claims.