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Mapp v. Ohio

Significance, Court Applies Exclusionary Rule To States, The Exclusionary Rule, Further Readings


Dollree Mapp


State of Ohio

Petitioner's Claim

That the state is barred from using evidence at trial that was obtained through an unlawful search and seizure.

Chief Lawyer for Petitioner

A. L. Kearns

Chief Lawyer for Respondent

Gertrude Bauer Mahon

Justices for the Court

Hugo Lafayette Black, William J. Brennan, Jr., Tom C. Clark (writing for the Court), William O. Douglas, Potter Stewart, Earl Warren

Justices Dissenting

Felix Frankfurter, John Marshall Harlan II, Charles Evans Whittaker


Washington, D.C.

Date of Decision

19 June 1961


The Court held that the exclusionary rule, which prevents unconstitutionally obtained evidence from being introduced at trial, applies to states as well as to the federal government.

Related Cases

  • Wolf v. People of the State of Colorado, 338 U.S. 25 (1949).
  • Elkins v. United States, 364 U.S. 206 (1960).
  • Schmerber v. California, 384 U.S. 757 (1966).


West's Encyclopedia of American Law. St. Paul, MN: West Group, 1998.

Additional topics

Law Library - American Law and Legal InformationNotable Trials and Court Cases - 1954 to 1962