This portion of the Fifth Amendment protects individuals from being “twice put in jeopardy of life or limb”—that is, in danger of being punished more than once for the same criminal act. The U.S. Supreme Court has interpreted the double jeopardy clause to protect against a second prosecution for the same offense after acquittal or conviction and against multiple punishments for the same crime.
Like other provisions in the Bill of Rights that affect criminal prosecutions, the double jeopardy clause is rooted in the idea that the government should not have unlimited power to prosecute and punish criminal suspects. Rather, the government gets only one chance to make its case.
www.justicelearning.org, The United States Constitution, what it says, what it means, A Hip Pocket Guide (Oxford University Press)