what is double jeopardy

Double jeopardy is a legal principle that protects a person from being tried twice for the same crime based on the same conduct. It is enshrined in the Double Jeopardy Clause of the Fifth Amendment of the U.S. Constitution, which prevents the government from prosecuting or punishing an individual multiple times for the same offense. This protection generally applies once jeopardy "attaches" in a trial, meaning after the jury is sworn in a jury trial or the first witness is sworn in a bench trial. The principle stops the state from retrying a person after acquittal, conviction, or certain mistrials, and also prevents multiple punishments for the same offense. However, there are exceptions, such as the dual sovereignty doctrine that allows different sovereigns (e.g., state and federal governments) to prosecute the same person for the same conduct without violating double jeopardy protections. Also, double jeopardy protections typically apply to criminal cases, not civil penalties unless they are punitive in nature. In summary, double jeopardy means one cannot be tried twice for the same crime after a legitimate trial outcome in the same jurisdiction.