Omar Mateen: Orlando gunman 'used gay dating apps and had visited Pulse nightclub before carrying out massacre'
The gunman who killed 49 people at Orlando's Pulse nightclub had previously visited the club and used gay dating apps, it has been claimed.
Regular customers said they had seen Omar Mateen in Pulse "several times" before Sunday's atrocity.
Others said they had been contacted by Mateen on gay dating app Grindr.
The FBI confirmed to NBC News that it was investigating the claims.
Mateen's father had claimed in the hours after the shooting that his son may have been motivated by his hatred for the LGBT community, recalling how he reacted angrily when he saw two men kissing in public.
Cord Cedeno told MSNBC that Mateen messaged him on Grindr but that he blocked him "immediately because he was very creepy".
Cedeno also said he "knew for a fact" that Mateen had visited Pulse on multiple occasions.
Ty Smith said he also recognised Mateen from previous nights at the club.
“Sometimes he would go over in the corner and sit and drink by himself, and other times he would get so drunk he was loud and belligerent," he said in an interview with the Orlando Sentinel.
Chris Callen, who worked at Pulse as a dancer, told The Canadian Press that Mateen had been visiting the club for at least three years.
US authorities said on Monday that Mateen was radicalised through the internet.
He pledged allegiance to so-called Islamic State shortly before Sunday's attack.
The group claimed responsibility, calling Mateen a "fighter", but President Obama said there was "no clear evidence" that he was directed to carry out the massacre by IS.