Mapp v. Ohio

June 19, 1961

Explanation of case

On May 23, 1957, police officers in a Cleveland, Ohio suburb received information that a suspect in a bombing case, as well as some illegal betting equipment, might be found in the home of Mapp. Three officers went to the home and asked for permission to enter, but Mapp refused to admit them without a search warrant. Two officers left, and one remained. Three hours later, the two returned with several other officers. Brandishing a piece of paper, they broke in the door. Mapp asked to see the “warrant” and took it from an officer, putting it in her dress. The officers struggled with Mapp and took the piece of paper away from her. They handcuffed her for being “belligerent.” Police found neither the bombing suspect nor the betting equipment during their search, but they did discover some pornographic material in a suitcase by Mapp's bed. Mapp said that she had loaned the suitcase to a boarder at one time and that the contents were not her property. She was arrested, prosecuted, and found guilty for possession of pornographic material.

Dollree Mapp was convicted of possessing obscene materials after an admittedly illegal police search of her home for a fugitive. She appealed her conviction on the basis of freedom of expression.


For Mapp: The police, who possessed no warrant to search Mapp's property, had acted improperly by doing so. Any incriminating evidence found during the search should, therefore, be thrown out of court and her conviction overturned. If the 4th Amendment did not limit the prerogatives of police on the local and State level, local law enforcement would have a mandate to search wherever, whenever, and whomever they pleased. The exclusionary rule that applied in federal courts should also be applied to State court proceedings.

For the State of Ohio: Even if the search was made without proper authority, the State was not prevented from using the evidence seized because “the Fourteenth Amendment does not forbid the admission of evidence obtained by an unreasonable search and seizure.” In other words, Ohio argued, the 14th Amendment does not guarantee 4th Amendment protections in the State courts. Furthermore, under the 10th Amendment, the States retain their right to operate a separate court system. The Bill of Rights only restricts and limits the actions of the National Government.

The Fourth Amendment prohibition against unreasonable searches and seizures, as applied to the states through the Fourteenth, excludes unconstitutionally obtained evidence from use in criminal prosecutions. Ohio Supreme Court reversed.

Mapp contended that her Fourth Amendment rights had been violated by the search, and eventually took her appeal to the nation’s highest court. Up to that time, unlawfully seized evidence had been banned from federal court prosecutions but not those in state courts.

Who won?

The U.S. Supreme Court ruled in a 5-3 vote in favor of Mapp. The high court said evidence seized unlawfully, without a search warrant, could not be used in criminal prosecutions in state courts.