• Mateen traveled to Saudi Arabia and the United Arab Emirates — before the FBI interviewed him in 2013
• A former co-worker reported Mateen’s extremism to their employer but no one took action… because Mateen was Muslim
• Last year, the FBI investigated Mateen’s connection to “the first American suicide bomber in Syria”
• Fox report: Mateen was enrolled in online courses from a notorious terrorist recruiter
• UPDATE – Two trips to Saudi Arabia
• Donald Trump and Hillary Clinton deliver dueling speeches on U.S. response to the attack
• Mateen’s wife knew he was planning an attack; told law enforcement one potential target was Disney World
• Local news station reports police will soon arrest an alleged accomplice
Those are just the bullet points read the whole article for details.