The latest edition of Engage, the Federalist Society's practice journal, includes a fascinating article by Roger Marzulla titled "Lenity: An Essential Rule for Interpreting Environmental Crimes Statutes." The article begins:
Unclear environmental laws and vague regulations defeat their stated purpose—environmental protection. The success of our framework of environmental laws and regulations depends on how well people follow the regulations’ mandates and prohibitions. But if no one can understand them, and no one knows what is required or prohibited, these laws will not achieve their intended result. The more complex the regulatory regime, the less clear the laws and regulations, and the more difficult it is for the most well-intentioned individual to comply because he or she cannot ascertain what is expected. Imprisoning people for unintentional violation of ambiguous laws and regulations undermines the principles of fairness, due process, and respect for the law—all of which underlie the legal rule called “lenity.”
The Rule of Lenity
The rule of lenity is a judicial doctrine that requires ambiguous criminal laws to be interpreted in favor of persons subjected to them.
This venerable rule not only vindicates the fundamental principle that no citizen should be held accountable for a violation of a statute whose commands are uncertain, or subjected to punishment that is not clearly prescribed. It also places the weight of inertia upon the party that can best induce Congress to speak more clearly and keeps courts from making criminal law in Congress’s stead.