I think that you can make it much, much more difficult to get a wrongful conviction in a case that's eligible for the death penalty though. I think that, for starters, all interactions with police should require video and audio, so that suspects can't be coercively questioned for 16 hours without an attorney before signing a "confession". I think any claimed evidence should have to have standards that were published, peer-reviewed, and repeatable before they could use it. And I think that crimes eligible for an imposed death penalty should have to take place over a period of time, rather than a single event. E.g., a robbery/murder shouldn't get the death penalty, but (per an earlier comment I made) a serial child rapist should. I would even say that you should be absolutely required to have forensic evidence in order to get a death penalty conviction; I believe that most exonerations were for convictions that relied on witness testimony, official misconduct, and coerced confessions, usually combined with an overworked and ineffective defense attorney.

I dunno; even the possibility of someone like Ed Kemper ever getting out--like if he ever tells the parole board that he thinks he's finally safe--is terrifying.