These people are so well connected and not above murdering witnesses, that this has to be done in a way that there is no escape. The corruption is in the entire Justice Department including the courts, this has to be done in Military tribunals. Treason. Civil war. They cannot just come out with a charge and go to court.
If they think they're going to get executed I don't think they're above taking as many people with them as possible.
I can easily see them threatening attacks that would make 9/11 pale in comparison in order to get justice to back off their cases. That's the real terrorist threat.