The gunman who killed 49 people in an attack on a gay nightclub in Orlando is said to have been a regular at the venue and had messaged several people on gay dating apps, according to reports According to The Orlando Sentinel, Omar Mateen visited the gay nightclub at least 12 times, a fact supported by 4 witnesses One Pulse regular, Kevin West, told the Los Angeles Times that Mateen messaged him on and off for a year using a gay chat app