Well this is ironic
We should know better than most that we can't stop every terrorist and every criminal every time and still live in a free country. Or we could have a dystopian surveillance state and "eradicate" crime.
The mother is stating that the FBI was looking into her son at one point some years ago. This does not translate to: the FBI has been watching his every step for the past five years. Another piece of irony is how much credit you are giving the FBI in that regard.
Thanks for sharing though.