The rule of lenity is a principle used in criminal law, also called rule of strict construction, stating that when a law is unclear or ambiguous, the court should apply it in the way that is most favorable to the defendant, or to construe the statute against the state. The rule of lenity stems from two constitutional objectives: first, the separation of powers, as it limits the scope of statutory language in penal statutes and does not allow the courts to establish the contours of a crime and its punishment. Second, the rule of lenity stems from the wish to “protect the legislature’s constitutional lawmaking prerogative, and to limit the courts’ encroachment on a legislative function”.
[Last updated in May of 2022 by the Wex Definitions Team]