'His Anger Was Constant': Orlando Gunman's Ex-Coworker Talks to 'Kelly File'

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Phil Keating reported new details this morning from Fort Pierce, Florida, outside the home of the terrorist who murdered 49 people Sunday at a gay Orlando nightclub.

FBI agents spent the night at Omar Mateen's apartment, removing a laptop and other electronic evidence. 

- Mateen, 29, worked as a security officer for G4S Solutions, which has been a major contractor for the Department of Homeland Security since 9/11, securing 90 percent of U.S. nuclear facilities.  

A former co-worker, Daniel Gilroy, told Megyn Kelly last night that Mateen was always angry and displayed stalker-like behavior. 

- Mateen's father, who posted YouTube videos in the past supporting the Taliban, spoke out, saying he does not support violence. 

"If he was alive today, I would ask him one question. As a parent, why did he do this, why?" he said about his son.

He said previously that his son became angry recently about seeing two men kissing in Miami.

- A former neighbor at the apartment complex reacted with shock, saying she remembers Mateen living with a girlfriend and a baby and that he once helped fixed her car.

"He was super sweet," said Tricia Adorno. "They were very sweet with me."

She said Mateen never mentioned anything about ISIS or radical Islam and that she was "shocked" when she saw his name on the news. 

Keating reported, however, that the overall reaction from neighbors was mixed.

- We also got a look at Mateen's Toyota Camry, which bears U.S. Marine Corps and NASA bumper stickers. 

Authorities are investigating whether those are an indication that he was pretending to be an ordinary American or whether he simply became radicalized. 

Watch the full America's Newsroom report above.

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