A growing body of academic literature discusses the problem of wrongful convictions — i.e., convictions of factually innocent defendants for crimes they did not commit. But how often do such miscarriages of justice actually occur? Justice Scalia cited a figure of 0.027% as a possible error rate. But the conventional view in the literature is that, for violent crimes, the error rate is much higher — at least 1%, and perhaps as high as 4% or even more.
This Article disputes that conventional wisdom. Based on a careful review of the available empirical literature, it is possible to assemble the component parts of a wrongful conviction rate calculation by looking at error rates at trial, the ratio of wrongful convictions obtained through trials versus plea bargains, and the percentage of cases resolved through pleas. Combining empirically based estimates for each of these three factors, a reasonable (and possibly overstated) calculation of the wrongful conviction rate appears, tentatively, to be somewhere in the range of 0.016%–0.062% — a range that comfortably embraces Justice Scalia’s oftencriticized figure.
If this Article’s tentative error-rate range is correct, it means that previous scholarship has significantly overstated the risk of wrongful conviction. Moreover, it is possible to compare the lifetime risk of being wrongfully convicted to the risk of being a victim of a violent crime. The relative risk ratio appears to be about 30,000 to 1. This decidedly skewed ratio suggests that reform measures for protecting the innocent may need to be cautiously assessed to ensure that they do not interfere with the important goal of prosecuting the guilty.
Cassell, Paul G., 60 Ariz. L. Rev. 815 (2018)