Under the Constitution, the federal government and state governments are separate sovereigns with their own laws and prosecutorial power. They can both bring charges for the same conduct without violating double jeopardy protections because they're enforcing different legal systems.
The Supreme Court reaffirmed this principle in 2022 with Denezpi v. United States, emphasizing that what matters for double jeopardy is the source of the law being enforced, not which prosecutor files charges. A person can be acquitted in state court and still prosecuted in federal court for the same conduct because the two prosecutions enforce different legal regimes.
This doctrine lets federal prosecutors step in when state courts fail—civil rights cases often rely on federal charges after state acquittals. But dual sovereignty also means the government gets multiple bites at the apple when it chooses. Courts apply strict limits: the state and federal offenses must rest on different legal authority, and one sovereign cannot use the other as an agent.
Dual sovereignty provides a backstop when state justice systems fail. Federal prosecutors can pursue civil rights violations when state courts won't, ensuring some accountability. But it also means citizens can face prosecution twice for the same conduct.
People often think double jeopardy prevents two trials for the same crime. It does—within one legal system. But state and federal governments are separate sovereigns, so two trials (one state, one federal) don't violate the principle.
Dual sovereignty provides a backstop when state justice systems fail. Federal prosecutors can pursue civil rights violations when state courts won't, ensuring some accountability. But it also means citizens can face prosecution twice for the same conduct.
People often think double jeopardy prevents two trials for the same crime. It does—within one legal system. But state and federal governments are separate sovereigns, so two trials (one state, one federal) don't violate the principle.