Did the FBI miss a warning before Florida school shooting?

The massacre at a Florida high school is again raising concerns about whether the FBI missed signs that might have stopped a mass shooting.
Last fall, a Mississippi bail bondsman and video blogger noticed a comment on one of his YouTube videos that said, “I’m going to be a professional school shooter.” He immediately reported it to YouTube and the FBI and the next day two agents came to his office to take a printout of the comment and ask him whether he knew anything about the