Definition - What does Double Jeopardy mean?
Double jeopardy refers to the act of prosecuting an individual more than once for the same offense after he or she has been acquitted, convicted, or punished for it. In the United States, the Fifth Amendment to the U.S. Constitution specifically prohibits double jeopardy.
Justipedia explains Double Jeopardy
The aforementioned provision in the Fifth Amendment to the U.S. Constitution is called the double jeopardy clause. Apart from the federal law, each of the U.S. states also has some sort of similar provision against double jeopardy in their statutes and constitutions. In Blockburger vs. United States (1932), a test was established that is now often used in cases involving double jeopardy. The test states that the government may separately try and punish the defendant for two crimes only if each crime contains an element that the other does not.