The Insanity Defense

Reading this case that was brought before the Supreme Court in 2006 made me think about the insanity defense. In a short sentence at the end of the article it is pointed out that the insanity defense is used in less the 1% of all cases and is successful less the a quarter of the time it is tried. One of the key points of the defendants argument is that state laws unfairly shifts the burden of proof from the State to the Defendant which runs counter to almost everything else in the legal system. As much as I think that people should pay for their crimes it seems wrong to not only hold someone who entire deck short of a deck of cards responsible for their actions, but to force them to prove that they are insane. This is further complicated when you consider Justice Souters question "What if he knew right from wrong, and knew it was wrong to kill aliens?" how do you handle people who are clearly nuts but are doing something wrong even within the standards set by their delusion. I honestly don't have an answer for this.