ORLANDO, Fla., June 12 (UPI) -- Law enforcement officials have identified Omar Seddique Mateen as the gunman in a mass shooting at Pulse nightclub in Orlando, Fla., that killed 50 people Sunday.
Mateen was known to the FBI as someone who sympathized with the Islamic State, but there was no indication of him planning to carry out an attack. Investigators also haven't found evidence linking him to the militant group also identified as Daesh, ISIS and ISIL.
FBI Assistant Special Agent in Charge Ronald Hopper said investigators were, "looking at all angles right now" to determine a motive.
"We do have suggestions that that individual may have leanings towards that, that particular ideology," Hopper said, referring to Islamic extremism. "But right now we can't say definitively, so we're still running everything around."
Mateen, who was born in New York and lived in Fort Pierce, Fla., was killed by police during a shootout. Law enforcement officials said he was armed with a handgun and an assault rifle when he opened fire at the nightclub around 2 a.m.
He worked as a private security guard and rented a car to drive to Orlando. Though twice interviewed by the FBI for making statements in support of, or having connections with Islamic extremists, neither investigation found enough evident of wrongdoing and where dropped.
Mateen was also a divorced father with a three-year-old son and was bullied during his own childhood.
"You could tell it hurt his feelings," said Brice Miller, who went to school with Mateen in Port St. Lucie, Fla., "but he would laugh it off."
"He was just dorky," Miller said. "He was disliked, but he always tried to get you to laugh."
As a security guard since 2007 for G4S, in Jupiter, Fla., he was licensed to carry a firearm. The company said in a statement is is cooperating fully with authorities.
He earned an associate's degree in criminal justice from nearby Indian River State College in 2006. He is seen wearing New York Police Department shirts in selfies on a MySpace page.
Sitora Yusifiy met Mateen online and they were married from 2009 to 2011. She described him as an abusive husband who repeatedly beat her
"He was not a stable person," she told The Washington Post. "He beat me. He would just come home and start beating me up because the laundry wasn't finished or something like that."
Shortly after the divorce, Mateen had a son with another woman who also apparently left him. She declined to comment.
Mateen's father, Seddique Mir Mateen, told NBC News that the he was unaware of any plans for his son to commit attack and added that it "had nothing to do with religion."
"We are saying we are apologizing for the whole incident," he said. "We weren't aware of any action he is taking. We are in shock like the whole country."
Seddique, an Afghan immigrant hosts a program called the Durand Jirga Show on YouTube where he has express some support for the Taliban. He said his son's violent act was not based on religion but rather anger from the sight of a pair of gay men kissing each other a few month ago.