Omar Mateen, the man believed to be behind the nation's deadliest mass shooting, was no stranger to the FBI. FBI Special Agent Ron Hopper, who runs the agency's Orlando office, says the 29-year-old was investigated—and cleared—twice, the Washington Post reports. In 2013, he was investigated for making "inflammatory comments to co-workers alleging possible ties to terrorists," Hopper says, and in 2014, the FBI investigated a possible link to American suicide bomber and fellow Fort Pierce, Fla., resident Moner Mohammad Abusalha and "determined that contact was minimal and did not constitute a substantive relationship or a threat at that time." Mateen reportedly pledged allegiance to ISIS after launching the massacre at the Pulse nightclub in Orlando, Fla., in which at least 50 people died. More details emerging on Mateen:
- Mateen held a license to work as a security guard and used a .223-caliber AR-15-type assault rifle and a 9mm semi-automatic pistol, authorities say. He was able to buy the weapons legally in the week before the shootings despite being on the FBI's radar, the Guardian reports.
- Mateen was a New York-born American citizen and the son of Afghan immigrants, reports Reuters. He worked as a security guard for a gated retirement community, and security firm G4S, which has employed him for nine years, says he passed two background checks.
- A law enforcement source tells the Daily Beast that there is no sign of any direct connection between Mateen and ISIS, which recently urged followers around the world to carry out attacks during Ramadan.
- Imam Syed Shafeeq Rahman of the Islamic Center in Fort Pierce says Mateen would pray there up to four times a week, sometimes bringing his young son, and didn't cause any trouble. "When he finished prayer he would just leave," Rahman tells the AP. "He would not socialize with anybody. He would be quiet. He would be very peaceful." He says he last saw Mateen on Friday.
- Sitora Yusufiy, Mateen's ex-wife, tells CNN that they married in 2009 and the relationship began to fall apart within months. She says he was bipolar and abusive, and she believes his mental illness, not his religious beliefs, caused him to carry out the massacre.
- A former police officer who worked with Mateen as a security guard for a year tells the Los Angeles Times that the man was extremely bigoted as well as "unhinged and unstable." "I complained multiple times that he was dangerous, that he didn't like blacks, women, lesbians, and Jews," says Daniel Gilroy. He says he quit his job after Mateen started harassing him with dozens of texts and phone calls a day and G4S did not intervene. "I saw this coming," he says.
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