Double jeopardy is the principle—known in Europe as ne bis in idem—that a person (including a corporation) should not be prosecuted twice for the same crime. In the United States, the principle is enshrined in the Fifth Amendment to the Constitution, which provides that “nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb.”

Notwithstanding its constitutional basis, the principle is subject to two interpretations in the United States that limit its effect.

First, the principle has long been subject to the “single sovereign” rule, and offers no protection if two different sovereigns engage in parallel or successive prosecutions. Thus under the current state of the law, if a person is convicted or acquitted in one state, that outcome does not bar further prosecution in another state, or by the federal government (and vice versa).