Definition
Double jeopardy is a Fifth Amendment protection that prevents a person from being prosecuted or punished more than once for the same offense by the same sovereign. It bars a retrial after an acquittal, a retrial after a conviction, and multiple punishments for a single offense. Its core purpose is to stop the government from repeatedly trying someone in hopes of eventually obtaining a conviction.
Legal Meaning
The Double Jeopardy Clause of the Fifth Amendment provides that no person shall "be subject for the same offence to be twice put in jeopardy of life or limb." Through the Fourteenth Amendment, this protection applies to the states as well as the federal government. Courts have read the clause to provide three distinct protections: against a second prosecution for the same offense after acquittal, against a second prosecution for the same offense after conviction, and against multiple punishments for the same offense.
A crucial concept is when jeopardy "attaches"—the moment at which the protection begins. In a jury trial, jeopardy attaches when the jury is empaneled and sworn. In a trial before a judge (a bench trial), it attaches when the first witness is sworn. Before that point, charges can typically be dismissed and refiled without triggering double jeopardy. Once jeopardy attaches and the case ends in an acquittal, the government cannot try the defendant again for that offense, even if new evidence later emerges and even if the acquittal seems mistaken.
The "same offense" question is governed by the Blockburger test, which asks whether each offense requires proof of a fact the other does not. If two charges each contain a unique element, they are not the "same offense," and prosecution for both is permitted. Double jeopardy is one of the most important shields in criminal defense, but it has well-established limits and exceptions that often surprise people.
Key Points
- Double jeopardy comes from the Fifth Amendment and applies to states through the Fourteenth
- It bars retrial after acquittal, retrial after conviction, and multiple punishments
- Jeopardy attaches when the jury is sworn, or when the first witness is sworn in a bench trial
- An acquittal is final—the government cannot retry even if new evidence appears
- The Blockburger "same offense" test compares the elements of each charge
- Under the dual-sovereignty doctrine, state and federal governments can each prosecute
- Mistrials and hung juries usually allow a retrial without violating the clause
- Double jeopardy does not apply to civil lawsuits over the same conduct
Real-World Example
A jury acquits Robert of robbery after a full trial. Months later, a witness comes forward with new evidence that strongly suggests Robert was guilty. Despite this, the state cannot retry Robert for that robbery—the acquittal is final, and double jeopardy bars a second prosecution for the same offense. However, if Robert's same conduct also violated a federal statute, the dual-sovereignty doctrine could allow the federal government to bring its own charges in federal court, because the federal and state governments are separate sovereigns. And regardless of the criminal outcome, the robbery victim could still sue Robert in civil court for damages, because double jeopardy does not apply to civil cases.
What Double Jeopardy Does and Does Not Bar
| Situation | Barred by Double Jeopardy? |
|---|---|
| Retrial after acquittal (same sovereign) | Yes—generally barred |
| Retrial after conviction (same sovereign) | Yes—generally barred |
| Multiple punishments for one offense | Yes—barred |
| State and federal prosecution for same act | No—dual-sovereignty doctrine |
| Retrial after a mistrial or hung jury | No—usually permitted |
| Retrial after defendant's successful appeal | No—usually permitted |
| Civil lawsuit after a criminal case | No—civil cases are separate |
Key Exceptions
Several important exceptions limit the protection:
- Dual sovereignty: Separate sovereigns—such as the federal government and a state, or two different states—may each prosecute the same conduct.
- Mistrials: If a trial ends in a hung jury or another manifest necessity, the prosecution can usually retry the defendant.
- Successful appeals: When a defendant wins reversal of a conviction on appeal, retrial is generally allowed because the defendant sought the new trial.
- Separate offenses: Under the Blockburger test, charges with different elements are not the "same offense" and may both be pursued.
- Civil and administrative proceedings: The clause applies only to criminal punishment, not civil suits or many regulatory actions.
Related Terms
Facing a Second Prosecution?
A criminal defense lawyer can determine whether double jeopardy protects you
Find Criminal Defense HelpWhen You Need a Lawyer
Whether double jeopardy applies can be complicated and case-specific. A criminal defense attorney can:
- Determine whether jeopardy attached and whether a prior proceeding ended on the merits
- Apply the Blockburger test to see if new charges are truly the "same offense"
- Assess whether the dual-sovereignty doctrine permits a second prosecution
- File a motion to dismiss charges that violate double jeopardy
- Advise you on the relationship between criminal charges and any civil lawsuit
To understand how a criminal prosecution differs from a civil suit over the same conduct, read our guide on civil versus criminal cases, and explore our criminal defense practice area.
Frequently Asked Questions
What does double jeopardy mean?
Double jeopardy is a constitutional protection under the Fifth Amendment that prevents a person from being prosecuted or punished twice for the same offense by the same government. It bars a second prosecution after an acquittal, a second prosecution after a conviction, and multiple punishments for the same crime. The goal is to prevent the state from repeatedly trying someone until it secures a conviction.
When does double jeopardy attach?
Jeopardy "attaches" at a specific point in the proceedings. In a jury trial, it attaches when the jury is sworn in. In a bench trial before a judge, it attaches when the first witness is sworn. Once jeopardy attaches, the protection against being tried again for the same offense generally applies, subject to certain exceptions like mistrials and appeals.
Can you be tried twice for the same crime in state and federal court?
Yes, under the dual-sovereignty doctrine. Because the federal government and each state are considered separate sovereigns, both can prosecute a person for the same conduct without violating double jeopardy. For example, an act may violate both a federal law and a state law, and each government may bring its own charges, though as a matter of policy prosecutors do not always do so.
Does double jeopardy apply if there is a mistrial or hung jury?
Generally no. If a trial ends in a mistrial because the jury cannot reach a verdict (a hung jury) or for other reasons of manifest necessity, the prosecution can usually retry the defendant. Double jeopardy does not bar a retrial when the first trial ended without a verdict on the merits, although it may bar retrial if the prosecution deliberately provoked the mistrial.
Can a person face both criminal and civil cases for the same act?
Yes. Double jeopardy applies only to criminal prosecutions, not civil lawsuits. A person acquitted of a crime can still be sued in civil court for the same conduct, because a civil case seeks money damages rather than criminal punishment and uses a lower burden of proof. The two proceedings are legally independent.