When Motorist Rodney King received more than 50 baton-strikes from police on a Los Angeles roadside in 1991, state charges against the four officers failed to produce convictions. But after another round of prosecution in which the federal government charged the officers with violating Mr King's civil rights, two of the attackers were sentenced to 30 months in prison. Ordinarily, the Fifth Amendment's prohibition on double jeopardy—“nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb"—shields individuals from being prosecuted (and punished) repeatedly for the same crime. Since 1850, though, the Supreme Court's “separate sovereigns” doctrine has permitted such dual prosecutions on the theory that each level of government gets to enforce its own laws.