Article I, Section 9, Clause 3:

No Bill of Attainder or ex post facto Law shall be passed.

The Supreme Court has rejected ex post facto challenges to sex offender registration laws and laws imposing civil commitment for “sexually violent predators,” holding that such laws are not penal in nature. For instance, in Kansas v. Hendricks, the Court rejected an ex post facto challenge to a statute allowing for civil commitment of “sexually violent predators,” in part because the statue was not punitive.1 The Court held that the civil commitment statute did “not implicate either of the two primary objectives of criminal punishment: retribution or deterrence.” On the contrary, the Court stated, “measures to restrict the freedom of the dangerously mentally ill” constituted “a legitimate nonpunitive governmental objective” and a “classic example of nonpunitive detention.” 2 In Seling v. Young, the Court rejected a claim that a civil commitment statute was punitive and thus ex post facto as applied to a particular individual.3 In Smith v. Doe, the Court denied an ex post facto challenge to the Alaska Sex Offender Registration Act.4 The Court relied in part on Hendricks to analyze whether the challenged law was punitive, concluding that the registration statute was civil and non-punitive in both purpose and effect.5

Footnotes

1

521 U.S. 346, 360–61 (1997). The Court also held that the statute was not retroactive. See ArtI.S9.C3.3.3 Retroactivity of Ex Post Facto Laws.

2

Id. at 361–63.

3

531 U.S. 250, 263 (2001).

4

538 U.S. 84, 95–106 (2003).

5

Id.