Kansas v. Hendricks

The Supreme Court reversed the Kansas Supreme Court's decision and upheld the law. Under the Fourteenth Amendment to the Constitution, a state may not deprive a person of life, liberty, or property without due process of law. Although it is written in terms of "process," the Supreme Court has interpreted the amendment to protect various substantive rights, not just procedural rights. This is known as "substantive due process." Based on earlier U.S. Supreme Court cases, the Kansas court concluded that substantive due process required that the state prove, before imposing civil commitment, that the person to be committed suffers from a mental illness, not merely a mental abnormality, and that the person is a danger to himself or others. The Supreme Court concluded that its earlier cases do not require "mental illness," and that it is sufficient if the state shows that the person suffers from a "mental abnormality" which makes the person unable to control his behavior and which makes him a danger to others. Because the Kansas law required such a showing, the Court concluded that it did not violate Hendricks rights to substantive due process.

The Supreme Court also rejected Hendricks's argument that the Kansas law imposed a criminal penalty which violated both the Ex Post Facto and Double Jeopardy Clauses of the Constitution. The Ex Post Facto Clause prohibits a state from imposing a criminal penalty on conduct which occurred before the law was enacted, while the Double Jeopardy Clause prohibits a state from punishing a person twice for the same conduct. Hendricks claimed that the Kansas law, as applied to him, violated these clauses because his crime occurred in 1984, ten years before the law was passed, and because he had already been punished for his crime by being sent to prison. The Court rejected these arguments because the Ex Post Facto and Double Jeopardy Clauses apply to only criminal penalties, and the Kansas law regarded only civil proceedings. In order to be a criminal penalty, a law must have either the purpose or effect of punishing a person. The Court concluded that the purpose of the Kansas law was not to punish violent sex offenders, but to treat them so that they can safely re-enter society. Justice Breyer, who was joined by three other justices, disagreed with the majority. Justice Breyer concluded that the real purpose of the Kansas law was to permanently confine violent sex offenders, and therefore the law violated the Ex Post Facto Clause as applied to Hendricks.

Importantly, however, all nine justices agreed that the law did not violate a sex offender's right to substantive due process. Thus, the Court's decision effectively validated the civil commitment laws in 16 other states which provided for civil commitment of violent sexual offenders. Also, the Court's decision opened the door for more legislative experimentation by the states in dealing with the problems posed by violent sexual assaults by repeat offenders.