Under both the 1994 Wetterling Act and the 2006 Sex Offender Registration and Notification Act (SORNA), Congress required certain convicted sexual offenders, including military personnel convicted of sexual offenses, to register their addresses with state authorities. SORNA tightened Wetterling Act provisions in some respects but made little change in the earlier statute's registration requirements. Both statutes reflected considerable evidence that sex-offender registration reduces recidivism and helps protect the public. In 1999, Anthony Kebodeaux (defendant), an Air Force servicemember, was convicted by a court martial for committing a sexual offense. Following Kebodeaux’s bad-conduct discharge and release from prison, Kebodeaux registered in Texas as a sex offender pursuant to the Wetterling Act. However, after SORNA's enactment, Kebodeaux violated the law by failing to inform state authorities of his change of address, for which the United States government (plaintiff) successfully prosecuted Kebodeaux in a federal district court. Kebodeaux appealed to the United States Court of Appeals for the Fifth Circuit, which reversed the district court. The government appealed to the United States Supreme Court, which granted certiorari.