In 1914 in Weeks v. United States, the U.S. Supreme Court unanimously ruled that evidence seized illegally in violation of the Fourth Amendment’s prohibition on unreasonable searches and seizures is inadmissible in federal courts. The so-called exclusionary rule was born. In 1949, the U.S. Supreme Court ruled in Wolf v. Colorado that the Fourth Amendment is incorporated by the due process of law clause of the Fourteenth Amendment and thus now applies to the states. However, the Court declined to apply the exclusionary rule to the states. Thus, evidence seized illegally in violation of the Fourth Amendment was still admissible against the accused in state courts.
In 1957, three Cleveland, Ohio, police officers arrived at Dollree Mapp’s home looking for a fugitive wanted for questioning in connection with a recent bombing and for evidence involving an illegal gambling operation. Mapp refused to admit them, and they had no search warrant authorizing a search of the premises. The officers left, but three hours later, police officers once more arrived at Mapp’s home and knocked on the door. When Mapp did not immediately answer, the police forced the door open and entered. Coming down the stairs from the second floor, Mapp demanded to see a search warrant. One of the officers held up a piece of paper, claiming that it was a warrant. Mapp snatched the piece of paper and stuffed it into her blouse. After a scuffle, the officers recovered the paper and handcuffed Mapp. The police then began a search of the entire house. Mapp’s attorney arrived but was refused entrance or access to his client. The police found no bombing suspect and no evidence of an illegal gambling operation. However, in the course of their search, they turned up some obscene material, possession of which was, at this time, a violation of Ohio law. At Mapp’s trial in an Ohio state court on a charge of possession of obscene literature, no search warrant was ever produced, nor was the failure to produce one explained. Following her conviction, Mapp appealed to an intermediate Ohio appellate court and then to the Ohio Supreme Court. Both Ohio courts upheld her conviction, and she then appealed to the U.S. Supreme Court.