Double jeopardy in law is a procedural defense that prohibits an individual from being tried or punished more than once for the same offense based on the same conduct. This means a person cannot be prosecuted twice for the same crime after an acquittal or conviction, nor can the state dismiss a case after trial has begun and then start over
. In the United States, this protection is guaranteed by the Double Jeopardy Clause of the Fifth Amendment to the Constitution, which states that no person shall "be subject for the same offense to be twice put in jeopardy of life or limb"
. Jeopardy "attaches" when a jury is sworn in a jury trial, when the first witness is sworn in a bench trial, or when a plea is accepted
. The rule applies broadly to all kinds of criminal charges, including felonies, misdemeanors, and juvenile adjudications, regardless of the potential punishment
. It protects individuals from multiple prosecutions for the same act, limits prosecutorial power, preserves the finality of criminal proceedings, and prevents the government from using its resources to harass defendants with repeated trials
. There are some nuances and exceptions, such as the "dual sovereignty" doctrine in the U.S., which allows different sovereigns (e.g., state and federal governments) to prosecute for the same conduct under their respective laws
. Also, double jeopardy does not bar prosecution for different offenses arising from the same conduct if the offenses require proof of different elements-for example, a person can be tried for both robbery and murder if the murder occurred during the robbery, but not for both murder and manslaughter for the same killing
. In summary, double jeopardy is a fundamental legal principle that ensures a person is not subjected to multiple prosecutions or punishments for the same criminal act, safeguarding individual rights and the integrity of the justice system.
