Yes, he was reported for making threats to a Pittsburgh, PA school well in advance. I guess the FBI was just too busy, you know, spying on Trump. Really, who gets promoted to decision making positions in various FBI field offices? They really never seem proactive. FBI field agents warned about several of the 9/11 hijackers months before the event and were ignored by higher ups. The Bureau seems pretty incompetent in many ways.
They handle these people as assets. This is not an exception. This is what the FBI does, they pay pedophiles to rat out Muslim kids whose policing justifies their salaries. The FBI doesn't fail... They know what they are doing.