The separate sovereigns doctrine, also called dual sovereignty, permits both state and federal governments to prosecute a defendant for the same conduct without violating the Fifth Amendment''s Double Jeopardy Clause. The doctrine rests on the principle that state and federal laws create distinct offenses because they derive from separate sovereign authorities. In Gamble v. United States (2019), the Supreme Court reaffirmed that "where there are two sovereigns, there are two laws, and two offences," making the source of legal authority an inherent feature distinguishing offenses. This means someone convicted of a crime under state law can face federal prosecution for the same act, or vice versa, as each sovereign enforces its own laws. The Court extended this principle in Denezpi v. United States (2022) to include tribal court prosecutions followed by federal charges. Critics argue the doctrine enables prosecutors to circumvent double jeopardy protections, but courts have consistently upheld it as constitutionally sound.