UPDATE 06/13/16 10:22 p.m.:A former classmate at Indian River Community College, who wishes not to be identified, says Omar Mateen was gay but closeted, Palm Beach Post reported. "We went to a few gay bars with him, and I was not out at the time, so I declined his offer," the former classmate said, claiming Mateen had asked him out. "He just wanted to fit in and no one liked him. He was always socially awkward."

See original story from 06/13/16 below.

Orlando, Fla. saw two horrific events over the weekend: 22-year-old YouTube star and the Voice contestant Christina Grimmie was gunned down by an alleged deranged fan on Friday during a meet and greet, and 49 were killed Saturday after lone gunman Omar Mateen opened fire at the gay nightclub Pulse. As more chilling details emerge from what is now the deadliest mass shooting in U.S. history, new reports say Mateen regularly attended the nightclub and that he messaged people through a gay dating app.

At least four witnesses have come forward saying they had seen the 29-year-old on multiple occasions, the Orlando Sentinel reported. "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," Ty Smith, who also goes by the name Aries, said. "We didn't really talk to him a lot, but I remember him saying things about his dad at times. He told us he had a wife and child."

"[He’d get] really, really drunk... He couldn’t drink when he was at home—around his wife, or family," Smith said. "His father was really strict... He used to bitch about it." 

"It’s the same guy," Chris Callen, who performs under the name Kristina McLaughlin, told the Canadian Press. "He’s been going to this bar for at least three years." According to Gawker, both Smith and Callen, who are married, say they stopped talking to him after he threatened them with a knife when someone joked about religion. "He said if he ever messed with him again, you know how it’ll turn out," Callen said.  

MSNBC host Chris Hayes tweeted that he spoke to a man who claims he and a friend received messages from Mateen through the gay dating app Jack’d.

Per the Orlando Sentinel, a Disney manager who prefers to remain anonymous says he was spotted at Walt Disney World—which is 15 minutes away from Pulse—back in April. FBI Director James Comey told the Associated Press they’re still working on figuring out if he was scouting the amusement park as a possible target.

Mateem, whose wife described him as "mentally disturbed," killed 49 and sent 53 to the hospital on Saturday night in what Orange County Sheriff Jerry Demings has declared a "domestic terror incident." He reportedly called 911 just before the attack to pledge his allegiance to the Islamic State and is said to have been angered by witnessing two men kissing. Since the incident, politicians, celebrities and regular citizens alike have spoken out and many throughout the country are paying tribute to the victims