Is it not the case that, in the eyes of the law, when someone is aware of
something and has the capability of taking action and does not, that individual
may be held responsible for that action?

Example: the driver of a getaway car may be held as an accomplice to murder.
	 The "I didn't know" defense spawned the "ignorance of the law is no excuse"

When an individual is held as a material witness to a crime, is there a criminal
charge against the individual?  If not, on what grounds is the person imprisoned?
