T.E.D., I must respectfully disagree with you on the DP. The standard of Proof for the DP is higher, and has been raised repeatedly for such crimes. It's VERY VERY hard these days to even arrest the wrong person for such a crime. Let alone convict them. Most of the "taken off Death Row" folks you hear about are because the defense finds a way to cast JUST enough doubt to get them life instead.
The better our science gets, the less and less likely someone innocent might even be arrested for such. Yeah, sometime, maybe... the guy standing NEXT to shooter might fry. BOO HOO. If you're stupid enough to be that intimately involved in a murder... too freaking bad man.