Also see the follow up comment by "Bryant" four entries after my initial comment; he provides several links that clear up the (that would be my ) confusion on the posse comitatus issue I mention.
Just to be clear; I think we are speculating about issues this event raises that there simply hasn't been time for any investigation to have more than superficially looked into yet. The focus to this point has been on capturing (or otherwise "apprehending") the two men. While esr makes an interesting (and perfectly valid) observation, I suggest we would all do well to let those in a position to ascertain an answer have the time to ask the necessary questions.
Which hopefully won't focus only on the easy and obvious possibilities.