It is pretty easy for us to be flippant about this case because it wasn't our best friend, mother, sister or daughter who was murdered by this certifiably dangerous man (allegedly).  The social contract we have living in a civilized society requires us not to personally administer our version of Justice (vigilantism) but to surrender that responsibility to the state.  in this situation the state failed to live up to its end of the bargain. 

Foreign policy has nothing to do with this topic and yes Kim Jung Il is my love child.