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 Dollree 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, found guilty, and sentenced for possession of pornographic material. No search warrant was introduced as evidence at her trial.
The question before the Court involved 4th Amendment protection against “unreasonable searches and seizures” and the “nationalization” of the Bill of Rights under the 14th Amendment. Was the search of Mapp's home legal and the evidence admissible under State law and criminal procedure? If the State criminal procedure code did not exclude the evidence as having been illegally gained, did Ohio law fail to provide Mapp her 4th Amendment protection against “unreasonable searches and seizures”? Weeks v. United States, 1914, established the exclusionary rule barring the admission of illegally obtained evidence in federal courts. Should that rule be extended, making evidence gained by an illegal search inadmissible in State courts as well?
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.
In a 6-3 decision, the Court overturned the conviction, and five justices found that the States were bound to exclude evidence seized in violation of the 4th Amendment. In the majority opinion, Justice Tom Clark declared: “We hold that all evidence obtained by searches and seizures in violation of the Constitution [is] inadmissible in a state court…. Were it otherwise…the assurance against unreasonable…searches and seizures would be [meaningless].”
Clark explained that “Only last year [Elkins v. United States, 1960] the Court…recognized that the purpose of the exclusionary rule 'is to deter—to compel respect for the constitutional guarantee in the only effectively available way—by removing the incentive to disregard it.'” The Court thus ensured that “in either sphere [State or federal]…no man is to be convicted on unconstitutional evidence.” The 4th Amendment sets the standards for searches and seizures by law enforcement officials in the United States, the Court noted, and the 14th Amendment requires judges to uphold those standards in every State.
Evidence gained by an illegal search became inadmissible in State courts as a result of the decision. The 50-year development of the exclusionary rule for illegal evidence, begun in the Weeks case, 1914, and continued in Elkins, 1960, culminated with the decision reached in Mapp, 1961.
The “Mapp Rule” has since been modified by decisions of the Burger Court, including Nix v. Williams, 1984 (inevitable discovery rule), and U.S. v. Leon, 1984 (“good faith” exception), so the exclusionary rule is no longer as absolute as when first handed down in Mapp. Critics of the Warren Court charged that it “had gone too far in interfering with police work.”