Fritz Allhoff, “Wrongful Convictions, Wrongful Acquittals, and Blackstone’s Ratio”, Australian Journal of Legal Philosophy 43 (2018):  39-57.

Abstract:  The British jurist William Blackstone opined that “it is better that ten guilty persons escape [punishment] than that one innocent suffer.”  While this aphorism—subsequently dubbed Blackstone’s ratio—has become a platitude of our criminal justice system, Blackstone leaves it unexplicated.  Rather, he presents the ratio casually, embedded as the fourth of five principles governing evidentiary rules, and with no discussion as to whether or why it is true.  Surely these are questions that should be engaged.  Furthermore, even granting the general idea that we should let the guilty escape rather than punish the innocent, why should we prefer a 10:1 ratio?  Or maybe the ratio is not even meant to support any critical weight, but rather just portends a more generic rhetorical device?  This essay explores such questions with an eye toward vindicating something like Blackstone’s ratio, albeit with more circumspect conclusions as to exactly what the ratio should be.