Old but worth reading: Malvo's Insanity Defense Is Nuts
Excerpt: Why does insanity always get you off the hook? It’s like a “Get Out Of Reality Free Card.” All you have to do is say you were a little cuckoo for Cocoa Puffs, and all of a sudden caring people with zero regard for the victim’s loved ones will convert some of their Delta miles and fly in to attend an anti-death penalty candlelight-vigil in your honor. All of a sudden people are feeling sorry for you, because you killed someone, because you were crazy! Of course you were crazy! That’s the point! Lawyers have to start passing on guys like this. When a guy admits to shooting a sixth grader on a playground as a goof, you have to walk away. Forget the quaint, secular notion that everybody deserves a defense for a second and actually hear what the guy is admitting to and rightly take a pass. And if anybody upbraids you about not upholding your constitutional duty or some crap like that, just tell them you were temporarily insane when you passed on the case.