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ORLANDO (CBSMiami) – A man who worshiped at the same mosque as the Orlando gunman says he never heard him say anything particularly hateful or homophobic, but he still reported him to the FBI.

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“The fact that this person was a Muslin I knew… very disturbing,” Mohammad Malik said.

Malik attends the same mosque in Fort Pierce that Omar Mateen frequented.

He says they met 10 years ago. However, over time, some of Mateen’s comments struck him as concerning – specifically references to videos of Anwar al-Awlaki, a radical Yemeni imam.

“He told me they were very powerful,” Malik said, “that raised the red flag even higher for me.”

Malik said he contacted the FBI, which investigated Mateen twice in two years, but eventually cleared him.

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Malik wants to debunk the idea that Muslims don’t report signs of radicalization.

“We do come forward. We help. I’m an example of that. I tried to do the right thing,” he said.

Law enforcement sources told CBS News that Mateen was a frequent user of online dating sites, looking for relationships with both men and women.

On Tuesday, US Attorney General Lorretta Lynch called the massacre an act of terror and of hate.

In addition to meeting with victims’ families, she also visited Pulse Nightclub.

Mateen was buried this week somewhere in Florida, but his family won’t say where.

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His father has only said his son had an Islamic ceremony and burial.