Sex offender registration and notification laws (SORAs) in the United States apply not only to those who commit sex offenses after the enactment of such laws, but also to those who committed sex offenses before those laws were enacted. However, the Ex Post Facto Clause of the Constitution prevents the retroactive application of a punitive law; this means that a person cannot be punished for a bad act that the person committed before the law punishing that act was enacted. Importantly, the Ex Post Facto Clause does not prohibit the retroactive application of a civil, regulatory—i.e., non-punitive—law. Thus, to survive constitutional scrutiny, SORAs must be deemed civil, regulatory measures that are designed to achieve a non-punitive goal. The federal courts—including the United States Supreme Court—have consistently characterized SORAs as just that: non-punitive, civil, regulatory measures designed to protect the innocent from dangerous sex offenders by deterring the commission of subsequent sex offenses.

Thus, the constitutionality of SORAs rests on two fundamental assumptions: (1) that sex offenders recidivate at very high rates; and (2) that restrictive SORAs actually reduce recidivism. The Sixth Circuit, in its Doe v. Snyder decision, which reviewed the constitutionality of Michigan’s SORA, carefully examined these assumptions and found that both were false. Federal government recidivism data and social science studies show that sex offenders—a category that includes not just those convicted of rape, but also includes a high school senior convicted of statutory rape because he slept with his underage high school girlfriend—do not recidivate at high rates. In fact, most sex offenders recidivate at low rates. Moreover, SORAs do not reduce recidivism; some studies even indicate that such laws may be causing recidivism rates to increase. Thus, the Sixth Circuit found that Michigan’s SORA unconstitutionally violated the Ex Post Facto Clause, in large part because it lacked a rational connection to a non-punitive purpose. This Article carefully examines the available data on sex offender recidivism rates, as well as the failure of the federal courts (prior to the Sixth Circuit’s Doe v. Snyder decision) to give much more than a passing glance at that data. This Article proposes that other federal courts should follow the Sixth Circuit’s example and carefully examine the factual justifications upon which the constitutionality of SORAs rests. Only then will the federal courts be able to protect the rights of United States’ citizens to be free from unconstitutional ex post facto punishment.