Are there any constitutional limits on the power of a legislature to restructure state-of-mind elements as affirmative defenses? The Supreme Court has suggested that such limits do exist, but has not clearly delineated what they are. However, an interesting habeas case now moving through the lower federal courts may provide a good opportunity to clarify this uncertain area of the law.

The case has emerged from a tug-of-war between the Florida legislature and the courts over the state’s basic drug-trafficking offense. Although the offense did not include any express state-of-mind element, the Florida Supreme Court held as a matter of statutory construction in 1996 that the state was required to prove knowledge of the illicit nature of the substance involved in the offense. The legislature responded in 2002 by amending the statute and clearly indicating that knowledge was not required; rather, the legislature specified, lack of knowledge must be proved by the defendant as an affirmative defense. (Apparently, only one other state, Washington, similarly dispenses with a state-of-mind element for drug trafficking.) Now, a federal district court has ruled on a habeas petition by a defendant convicted under the Florida statute, holding in Shelton v. Secretary, Department of Corrections (No. 6:07-cv-839-Orl-35-KRS) that the new version of the offense facially violates the Due Process Clause.

I’m sympathetic to the idea of constitutional limits on the legislature’s ability to create strict-liability crimes, but the court’s reasoning in Shelton strikes me as something less than compelling.