I may be wrong here but... they've got 100% proof theo tonin is involved now, what with the helicopter and several corroborating witnesses (Wynn Duffy, Drew, Boyd, Johnny, Colt, Ava, all would confess to it to save their ass, especially Ava trying to protect Boyd).
So why don't they call up the FBi and get not just a few guys, but a convoy with a tank or two to take down one of the most powerful terrorists in america? Yeah, I think DC would be down for that don't you?
or would that make the story too easy <_<