Recidivism is one protection afforded by capital punishment but I think the far larger benefit is in the deterrence of would be murderers. I asked the anti capital punishment crowd for examples of innocent folks who have been executed. Bells responded with 5 examples, 2 of which occurred nearly a century ago. The most recent conviction occurred more than 2 decades ago and the execution occurred more than a decade ago. In all of the cases there is no proof of innocence. In the 2 older cases which are nearly a century old there is certainly overwhelming evidence justice was not served and the evidence of guilt was weak at best. Those cases are a clear miscarriage of justice which would now not be tolerated. Under current rules, those 2 cases would have been thrown out of court and the individuals would not have been even tried. But Bells had to go back nearly a century to find those 2 cases. Criminal justice has changed dramatically since then. Rules of interrogation have changed (e.g. Miranda Rights). There was the whole civil rights movement. So it isn't reasonable to equate the current judicial system with the judicial system of the early 20th century. James R and I had a discussion with respect to error rates earlier. James cited a study indicating a 4% conviction error rate. I haven't found any relevant evidence of wrongful executions.