Kansas v. Hendricks

Leroy Hendricks (defendant), a repeat child sex offender, was brought before Kansas courts under the state's Sexually Violent Predator Act, which allows civil commitment of people likely to commit predatory sexual violence because of a mental abnormality. The trial court ordered Hendricks committed based on his own admission of incurable pedophilia, which it found qualified as a mental abnormality. Hendricks argued the Act violated the Double Jeopardy and Ex Post Facto Clauses because it effectively imposed a second, retroactive punishment on him, and the Kansas Supreme Court agreed, striking the Act down as a substantive due process violation. Kansas sought review in the U.S. Supreme Court.