Feds scramble to learn more about mass-murderer Omar Mateen

CHICAGO (FOX 32 News) - Federal authorities are scrambling to learn more about 29-year old mass-murderer Omar Mateen, who in his 911 call swore allegiance to the Islamic State.

Mateen was no stranger to federal authorities. He was interviewed by the FBI on multiple occasions.

Mateen's family immigrated to the US from Afghanistan, but he was born in New york and later moved to Florida where he graduated from college. He had a job as a security guard at a facility for juvenile delinquents.

Mateen's ex-wife describes him as violent and unstable, and claims he beat her. A friend says following their divorce, Mateen slowly became more religious, even taking a pilgrimage to Mecca. The FBI first became aware of Mateen in 2013 when he made inflammatory comments to co-workers alleging possible terrorist ties.

"The FBI thoroughly investigated the matter,bincluding interviews of witnesses, physical surveillance and records checks...in the course of the investigation, Mateen was interviewed twice...ultimately we were unable to verify the substance of his comments and the investigation was closed," officials said.

Mateen was investigated again by the FBI in 2014 for his alleged ties to a known American suicide bomber, but again they did not find Mateen to be a threat. The questions that authorities are asking now is were there signs investigators should have caught? And was Mateen self-radicalized or did he act as part of a known terror cell?

"There is a connection to some Islamic radicalism. But we still don't know the facts. We're going to be very deliberative in what we end up telling you, so that we don't overstate it," said Bill Nelson.

Mateen's father, Seddique, who has strong political ties to Afghanistan and hosts a local political show on television, claims the mass shooting was not religiously motivated and that he personally witnessed his son's outrage when they witnessed two men publicly kissing inside a bathroom in Miami.