You forgot the pacing off distances around a national monument...not the average tourist thing to do. He should have been questioned...just as I was questioned at a police road block last Saturday night for doing nothing more than driving my car. But, I understand your position that we should wait until he blows up the Washington Monument and then question him...makes sense to me.(sarcasm off)
We should question the pacing tourist.
We should also question everyone at the police roadblock.
Heck, we should question everyone buying a gun, and/or ammo.
Food can be a weapon too, as a Somalian warlord used once. We should question everyone buying groceries too. (sarcasm off)