Wayne A. Logan


This Article explores the history of the Ex Post Facto Clause, including the Supreme Court's seminal 1798 decision in Calder v. Bull, and analyzes the results of a survey of ex post facto claims decided in state courts from 1992-2002, the first study to catalog the types of claims generated among the states, and the institutional response of state courts to them. The author provides an overview of the claims resolved in state courts, examining the nature of the laws challenged, how the challenges fared, and the rationales used by courts in their dispositions. Discussion focuses on two abiding sources of confusion in ex post facto jurisprudence: the interpretation of the categories of laws the Calder decision prescribed as being ex post facto, and the ongoing uncertainty over the definition and treatment of laws deemed procedural (as opposed to substantive) in nature. These areas of uncertainty, it is argued, not only inspire confusion among the courts, but also serve to undermine the crucial structural role of the Ex Post Facto Clause itself- intended by the Framers to guard against the potent political forces motivating state legislatures to adopt criminal laws with retroactive effect.