In Rehaif v. United States, the United States Supreme Court issued an opinion in a case involving a prosecution under 18 U.S.C. §922(g) and §924(a)(2), which are federal statutes that criminalize possession of firearms by a person falling into any of nine categories.

In this type of prosecution, the Supreme Court held that the government must prove both that the defendant knew he possessed a firearm and that he knew he belonged to the relevant category of persons prohibited from possessing a firearm. In this case, an undocumented immigrant was charged with being in possession of a firearm, so prosecutors must prove not only that he knew he possessed a firearm or ammunition, but also that he knew his immigration status made him ineligible to have the prohibited item.

Interestingly, Justices Alito and Thomas dissented partly because they were concerned that the Court’s decision would lead to a flood of challenges by people currently incarcerated under Section 922(g).