United States v. Leon

law case

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Last updated

July 14, 2026

Quick Summary

In the U.S. legal case U.S. v. Leon (1984), the Supreme Court established a "good faith" exception to the exclusionary rule. This rule generally prevents the use of evidence seized by police in violation of the Fourth Amendment against a criminal defendant.

The Court reasoned that excluding evidence obtained with a search warrant, even if later found to be invalid, carried an unacceptable social cost. This decision allows evidence to be admissible if officers acted in "good faith" when obtaining the warrant, balancing the need for effective law enforcement with the protection of individual rights against unreasonable searches and seizures.12

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exclusionary rule
…under legal attack, and in U.S. v. Leon (1984) the Supreme Court held that evidence obtained “in good faith” with a search warrant later ruled invalid was admissible. A central argument was the unacceptable social cost of excluding such evidence, a reason subsequently given for creating further exceptions to the…
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…under legal attack, and in U.S. v. Leon (1984) the Supreme Court held that evidence obtained “in good faith” with a search warrant later ruled invalid was admissible. A central argument was the unacceptable social cost of excluding such evidence, a reason subsequently given for creating further exceptions to the…
Read More