It was unclear whether Mateen was on the FBI's radar before the attack. However, when asked about possible connections to radical Islamic terrorism, assistant FBI Agent in Charge Ronald Hopper told Fox News, "We do have suggestions that that individual may have gleanings toward that particular ideology. But right now we can't say definitively."
Hopper also said Mateen made "threats in the past that he has ties to terrorist organizations."
http://www.foxnews.com/us/2016/06/12...l?intcmp=hpbt1
Common sense, if a muslim makes threats and says he tied to islamic terrorist organizations, take it seriously.
FBI Agent in Charge Ronald Hopper, you're an idiot.