[quote]good read on Mens rea if you wish to do so...
http://en.wikipedia.org/wiki/Mens_rea[/quote]
then just one page over from there...
Willful blindness is a term used in law to describe a situation in which an individual seeks to avoid civil or criminal liability for a wrongful act by intentionally putting himself in a position where he will be unaware of facts which would render him liable. For example, in a number of cases, persons transporting packages containing illegal drugs have asserted that they never asked what the contents of the packages were, and therefore lacked the requisite intent to break the law. Such defenses have not succeeded, as courts have been quick to determine that the defendant should have known what was in the package, and exercised criminal recklessness by failing to find out before delivering it.
http://en.wikipedia.org/wiki/Willful_blindness