This blog seeks to explain two basic concepts in criminal law which tends to lead to significant confusion: double jeopardy, and dual sovereignty.
Double jeopardy is a constitutional principle that comes from the double jeopardy clause in the Constitution’s 5th Amendment. It means that you may not be charged or prosecuted for the same crime twice. For example, if you were charged with the murder of Mr. Smith, went to trial, and were found innocent, you may not later be charged again with the murder of Mr. Smith if new evidence surfaces against you for the crime. You may be charged for other crimes, such as robbing and assaulting Mr. Smith, or conspiring to kill Mr. Smith, but not murdering Mr. Smith.