The multiple sovereigns doctrine is a legal principle that allows for a defendant to be prosecuted by different jurisdictions for the same conduct without violating the double jeopardy clause. This means that if a crime violates both state and federal laws, a person can be tried in both courts without it being considered double jeopardy. This doctrine underscores the idea that different sovereigns—like state and federal governments—have their own legal systems and can impose separate penalties for the same act.