Omar S. Mateen, who killed 50 people at a gay nightclub in Orlando last night, had already been "on the radar" of US officials, and reportedly pledged allegiance to ISIL, a.k.a. the Islamic State, in a 911 call just before the attack.
Mateen had twice been identified as a "person of interest to authorities," a senior law enforcement source told The Daily Beast. He came to the FBI's attention in 2013 and again in 2014, though the source didn't specify why. The FBI opened an investigation into Mateen but couldn't find anything requiring further work, and so closed the case, according to The Daily Beast source. In a conflicting account, law enforcement officials told ABC News that Mateen was "on the radar" of officials, but not subject to a specific investigation.
Before carrying out the attack, Mateen called 911 in Florida and swore his allegiance to the head of the Islamic State, Abu Bakr al-Baghdadi, according to NBC News, which cited law-enforcement sources. A US congressman, Adam Schiff, told CNN he had been given the same information by intelligence officials.
Mateen was born in New York in 1986 to Afghan parents and was once married to a woman from New Jersey. His former wife told The Washington Post that Mateen was violent, mentally unstable, and often beat her. "He would just come home and start beating me up because the laundry wasn't finished or something like that," she said. The couple were married in March 2009 and formally divorced in 2011.
The 29-year-old worked as a professional security officer, and had a gun license to carry a firearm. He lived in Port St. Lucie, Florida, a two-hour drive from Orlando, and rented a car to drive there and carry out the attack.
Aside from the report about Mateen's ISIL ties, the exact motives behind his attack remain unclear, and it is also unclear whether he collaborated with anyone. So far, the authorities have not released any answers. Florida Democrat senator Bill Nelson has said information from intelligence sources suggest "a link to Islamic radicalism… some kind of connection to ISIS," a.k.a ISIL. However, Florida congressman Alan Grayson said there was currently no evidence that Mateen had outside help.
One possibility is that Mateen was a lone wolf inspired by radical Islam but not working directly with any terrorist groups. The Islamic State recently called on followers to attack the United States and Europe during the holy month of Ramadan, which began June 5.
Mir Seddique, Mateen's father told NBC News that "this had nothing to do with religion." He said it might have been because Mateen had seen two men kissing in Miami a couple of months earlier in front of his wife and son, and became angry.