I would be in favour of the death penalty for particularly heinous crimes (e.g. premeditated murder) if it weren't for how common wrongful convictions are. (I'm not sure how common they actually are, I've watched a lot of documentaries on this recently so probably have a skewed idea.)

I'd also be in favour of chemically castrating convicted rapists and child-molesters, but again, probably not a good idea for the same reason.