In his Commentaries on the Laws of England, William Blackstone declared, “It is better that ten guilty persons escape, than that one innocent suffer.” In an 1785 letter, Benjamin Franklin was even more exacting: “That it is better 100 guilty Persons should escape, than that one innocent Person should suffer, is a Maxim that has been long and generally approv’d, never that I know of controverted.”
In 2011, the U.S. Department of Education took a different position. The department instructed colleges and universities to use preponderance of the evidence rather than clear and convincing evidence when considering accusations of sexual assault on their campuses.
So how high a risk of false conviction do the innocent face under the department’s guidance standards? John Villasenor, a professor of public policy at the University of California, Los Angeles, set out to answer that in a study that uses probability theory to model false convictions under the preponderance of the evidence standard. What he found should take all fair-minded Americans aback.