Federal law codified at 18 U.S.C. § 922(g) bars specific categories from possessing firearms or ammunition: anyone convicted of crimes punishable by over one year imprisonment, unlawful drug users or addicts, people adjudicated mentally defective or committed to mental institutions, those under domestic violence restraining orders, and anyone convicted of misdemeanor domestic violence. States add restrictions for violent felonies, firearm-related crimes, hate crimes, and individuals found to pose significant danger to themselves or others. In the 2008 Heller decision, the Supreme Court noted "nothing in our opinion should be taken to cast doubt on longstanding prohibitions on the possession of firearms by felons," but subsequent rulings created uncertainty. After the 2022 Bruen decision, some courts ruled history only supports disarming people with violent convictions, not nonviolent felonies like mail fraud. Convicted felons can regain gun rights through pardons or expungement. The constitutionality of these restrictions remains heavily litigated as courts debate which prohibitions the Second Amendment permits.