Legal jeopardy is being exposed to the danger of a conviction and punishment in a court of law. Double jeopardy is a defense that can be raised in a criminal prosecution. The general rule of double jeopardy bars a second prosecution for the same offense. Courts have carved out many exceptions to this fundamental rule of constitutional law, but in Monge vs. California, the U.S. Supreme Court said that double jeopardy can attach in three circumstances. First, a person can’t be prosecuted a second time after they were found not guilty of the same offense. They can’t be prosecuted for that same offense again either if they were already found guilty. Third, there can’t be multiple punishments for the same offense.

Origin of double jeopardy

The roots of the notion of double jeopardy are so deep that it’s origin isn’t completely clear. It may have came over on the Mayflower. The charter of liberties for the Massachusetts Bay Colony specifically addressed it in 1641. That charter provided the framework for the Bill of Rights. Both before and after independence, colonies recognized or adopted the prohibition through their case law in the courts. It was made part of the 5th Amendment to the U.S. Constitution in 1791 where it was stated that “nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb.” It remains a fundamental premise of American law nearly 225 years later.

How double jeopardy is used today

The two basic rules involving double jeopardy in a court of competent jurisdiction involve when it attaches. In a bench trial when a judge hears all of the evidence and determines guilt or innocence, jeopardy attaches when the first witness is sworn in. In a jury trial, it attaches whe2n the jury is sworn in. Double jeopardy doesn’t stop a federal prosecution after a not guilty verdict in a state prosecution. It doesn’t operate as a bar to another trial if a defendant appeals a conviction successfully, but prevailing in an appeal on a lesser charge like second degree murder would preclude a new trial on a new charge of first degree murder. Should an appellate court find that a conviction was based on insufficient evidence, another prosecution isn’t permitted. Fifth Amendment double jeopardy protection doesn’t apply in the case of a deadlocked jury, nor does it apply in the case of a mistrial if the defendant moved or consented to it, since the trial is deemed to have had no legal effect and invalid. Another trial might not be permitted if the defendant objected to the mistrial or did not otherwise consent to it. Another prosecution won’t be permitted if the mistrial was declared as a result of prosecutorial or judicial misconduct.

Since the purpose of the Fifth Amendment protection against double jeopardy is to prevent the burden of two or more trials, a defendant who raises double jeopardy objections before the commencement of a trial can ordinarily immediately appeal an adverse ruling. This exception is contrary to the general rule that doesn’t permit appeals of orders that aren’t final. Otherwise, the primary area contested turns on the bench or jury trial and when jeopardy attaches prior to judgment.