In the United States, civil confinement is a term for the formal legal process by which persons convicted of certain sexual offenses (generally violent sex offenders) may be subject to involuntary commitment upon completion of a prison sentence.
Although the exact details of the legal process may vary from state to state, the United States Supreme Court reviewed and upheld as constitutional a statutory process adopted in Kansas. See Kansas v. Hendricks, 521 U.S. 346 (1997). There, civil confinement proceedings could be initiated against "any person who has been convicted of or charged with a sexually violent offense and who suffers from a mental abnormality or personality disorder which makes the person likely to engage in the predatory acts of sexual violence." Many of those terms were themselves defined in the statute, including "mental abnormality," defined as "congenital or acquired condition affecting the emotional or volitional capacity which predisposes the person to commit sexually violent offenses in a degree constituting such person a menace to the health and safety of others." Id.
If a prison identified an inmate who was about to be released but potentially fit this definition, the prison authorities were required to notify the local prosecutor of the impending release. The prosecutor was then required to decide whether to petition for commitment. The court would then have to determine whether probable cause existed to support the inmate's status as a "sexually violent predator," and, upon such a determination, order the inmate to be psychologically evaluated. The psychological evaluation would then form the basis of a further trial to determine whether the inmate qualified as a violent sexual predator. Upon such a determination, the inmate would be subject to involuntary commitment at a medical facility until such time as his mental abnormality had changed and it was safe to release him. Id. at 353. The court would then be required to conduct an annual review of the determination, and the inmate would always be allowed to petition for freedom under the same standards. The Supreme Court concluded that this process met previously established standards of constitutional substantive due process governing voluntary confinement, did not constitute double jeopardy because the proceedings were civil rather than criminal, and was not an ex post facto law for the same reason. Id. at 353-371. In a following case, the United States Supreme Court clarified that the government must demonstrate that the inmate has at least a serious lack of ability to control his behavior. Kansas v. Crane 534 U.S. 407 (2002). The Supreme Court has also determined that Congress has the authority to pass a similar law affecting federal prisoners. United States v. Comstock, 560 U.S. 126 (2010).
Twenty states have civil commitment facilities, as of 2018.
As with civil commitment generally, civil confinement is a controversial implementation of state power. Detractors point to the prospect of indefinite detention without due process of law. Proponents cite public safety.
State legislatures who have decided to adopt civil confinement statutes have expressed the intent of the laws in their enactments. One example is the state of Washington, which explained:
Even after serving decades-long sentences, sex offenders are often held indefinitely in prison-like conditions—a situation that critics say is legally and ethically dubious.