---
title: "Double Jeopardy"
type: Legal Rule
source: https://casebriefly.com/legal-rules/double-jeopardy
---

# Double Jeopardy

The Double Jeopardy Clause of the Fifth Amendment prohibits a second prosecution for the same offense after acquittal, a second prosecution for the same offense after conviction, and multiple punishments for the same offense in a single proceeding.

## Definition

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." This constitutional protection encompasses three distinct guarantees: protection against a second prosecution after acquittal, protection against a second prosecution after conviction, and protection against multiple punishments for the same offense. The clause applies to the states through the Fourteenth Amendment.

Jeopardy "attaches" at a specific point in the proceedings, after which the protections apply. In a jury trial, jeopardy attaches when the jury is empaneled and sworn. In a bench trial, it attaches when the first witness is sworn. In a plea proceeding, it attaches when the court unconditionally accepts the guilty plea. Before jeopardy attaches, the government may dismiss and refile charges without constitutional limitation.

The Blockburger test, from Blockburger v. United States, is the primary test for determining whether two offenses are the "same offense" for double jeopardy purposes. Under this test, two offenses are considered different if each requires proof of an element that the other does not. If each offense contains an element not found in the other, they are separate offenses and can be prosecuted and punished separately. The separate sovereigns doctrine provides that successive prosecutions by different sovereigns (federal and state governments, or two different states) do not violate double jeopardy because each sovereign has independent authority to enforce its laws. A mistrial generally does not bar retrial if it was declared due to manifest necessity (such as a hung jury), but it may bar retrial if caused by prosecutorial misconduct intended to provoke a mistrial.

## Elements

- Protection against a second prosecution after acquittal for the same offense
- Protection against a second prosecution after conviction for the same offense
- Protection against multiple punishments for the same offense in a single proceeding
- Jeopardy must have attached (jury sworn, first witness sworn, or plea accepted)
- The Blockburger same-elements test determines whether offenses are the same or different

## Key Case

Blockburger v. United States, 284 U.S. 299 (1932)

## Landmark Cases

| Name | Citation | Significance |
| --- | --- | --- |
| Blockburger v. United States | 284 U.S. 299 (1932) | Established the same-elements test for determining whether two offenses are the same for double jeopardy purposes |
| Gamble v. United States | 587 U.S. 678 (2019) | Reaffirmed the separate sovereigns doctrine, allowing successive federal and state prosecutions for the same conduct |
| Ashe v. Swenson | 397 U.S. 436 (1970) | Incorporated collateral estoppel into the Double Jeopardy Clause, barring relitigation of issues necessarily decided in the defendant's favor |
| Oregon v. Kennedy | 456 U.S. 667 (1982) | Held that retrial after a defense-requested mistrial is barred only if the prosecution intentionally provoked the mistrial |
| Brown v. Ohio | 432 U.S. 161 (1977) | Applied the Blockburger test to hold that a lesser included offense and the greater offense are the same offense for double jeopardy purposes |

## Exam Tips

- Apply the Blockburger test carefully: if each offense requires proof of an element the other does not, they are separate offenses
- Remember the separate sovereigns doctrine; federal and state prosecutions for the same conduct do not violate double jeopardy
- Know when jeopardy attaches: jury sworn (jury trial), first witness sworn (bench trial), or plea accepted (plea proceeding)
- Distinguish between mistrials for manifest necessity (retrial permitted) and those caused by prosecutorial bad faith (retrial barred)

## Common Mistakes

- Assuming double jeopardy bars any second trial; retrial is permitted after a hung jury mistrial, a successful appeal by the defendant, or prosecution by a separate sovereign
- Misapplying the Blockburger test; two charges arising from the same conduct can be separate offenses if each requires proof of a unique element
- Forgetting the separate sovereigns doctrine; a state prosecution following a federal prosecution for identical conduct does not violate double jeopardy

## Mnemonic Or Memory Aid

"Once acquitted, always acquitted" -- the strongest protection of double jeopardy is that an acquittal is absolutely final and cannot be appealed by the prosecution

## Related Rules

- homicide-degrees-of-murder
- felony-murder-rule
- conspiracy
- robbery-vs-larceny-vs-burglary

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Source: [Double Jeopardy — CaseBriefly](https://casebriefly.com/legal-rules/double-jeopardy)