Here's What We Know About the Orlando Gunman Omar Mateen

Further details are emerging about the gunman behind the Orlando massacre.

Further details are emerging about the gunman behind the Orlando massacre.

Omar Mateen, a 29-year-old married father and security guard, opened fire inside the Pulse nightclub in the early hours of Sunday, killing 49 people and injuring more than 50 others. Police then shot him dead.

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He was born in Flushing, New York, to Afghan refugees. He wanted to become a cop and posted photos of himself in NYPD t-shirts, although he had no actual link to the NYPD.

After the killings, his ex-wife, Sitora Yusifiy, told reporters in Colorado that she had met Mateen on social media and was married to him for just four months in 2009. She left him because he beat her for not doing the laundry, she said. 

“My family literally rescued me,” she said. “They had to pull me out of his arms. I left all my belongings.”

They were divorced in 2011.

“He was mentally unstable and mentally ill," she said. "That's the only explanation I can give and he was obviously disturbed.”

Mateen married for a second time and has a 3-year-old son.

He lived in Port St. Lucie, Florida, where he worked as a security guard at a courthouse and at the security gate of an upscale gated community just outside Orlando.

A former co-worker recalled how Mateen spoke about hating gay people and other minorities.

"This guy was unhinged and unstable," Daniel Gilroy told Florida Today. "He talked of killing people."

In 2012, Mateen made a pilgrimage to Mecca. He was questioned by the FBI twice for alleged links to ISIS – but he was cleared.

"The FBI first became aware of Mateen in 2013 when he made inflammatory comments to co-workers alleging possible terrorist ties," Special Agent Ronald Hopper told reporters on Sunday.

Read: Pope Francis Joins Obama, Others in Chorus of Condemnation Against Orlando Attack

"The FBI thoroughly investigated the matter including interviews with 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."

Mateen had a gun license in Florida and was able to obtain two weapons legally shortly before the attack.

When questioned about how Mateen was able to buy the guns in light of his history with the FBI, Hopper only said that the investigation into Mateen’s radical ties had been "inconclusive."

"It has been reported that Mateen made calls to 911 this morning in which he stated his allegiance to the Islamic State," he said. "We're looking into any and all connections both domestic and international."

The shooter’s father, Seddique Mateen, is host of a bizarre YouTube show aimed at his native country, where he claims to be running for president. He has also expressed support for the Taliban.

He told NBC that he visited his son hours before the massacre.

“At two o’clock he became another person,” he said.

Mateen Sr. added that his son previously became upset when he saw two men kissing in Miami.

Watch: How to Use a Folding Chair to Barricade the Door During a Shooting