There's also the fact that a wrong person convicted usually means the guilty party going free and the investigation closed. This is bad enough normally but the

There's also the fact that a wrong person convicted usually means the guilty party going free and the investigation closed. This is bad enough normally but the death penalty creates even bigger incentives for people to claim the right person was convicted after the fact and not to look too closely at any new evidence which comes to light which could lead to the actually guilty party being found.