[throwaway5752]

This isn't some hypothetical challenge. There's only a few hundred known cases in the US and most of the dismissals are recent because of the feasibility and availability of PCR and other DNA amplification techniques. Anyone could exhaustively read through every case in a few days (which seems to be only fair when you're talking about taking people's lives).

Here's a list, for example: https://deathpenaltyinfo.org/innocence-cases

edit: and why would you expect differently about suicide rates? Prison is awful. It is punishment, and it the punishment doesn't end after you have left because loss of vote, inability to work in many fields, social stigma, and broken relationships. However, generally speaking, most people in prison are guilty (even if many are not). It is a distinctly different group than people than those exonerated after a death sentence, who are invariably not guilty and they know it. The two groups aren't comparable even though one is a subset of the other.