Mapp v. Ohio was a landmark Supreme Court case that was decided in 1961. The case involved Dollree Mapp, a woman who was convicted of possessing obscene materials after police officers conducted a search of her home without a warrant. Mapp appealed her conviction, arguing that the search violated her Fourth Amendment rights, which protect against unreasonable searches and seizures.
The Fourth Amendment states that "the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
The case began when police officers in Cleveland, Ohio received a tip that a bombing suspect was hiding at Mapp's home. The officers arrived at Mapp's home and demanded to be allowed inside to search for the suspect. Mapp refused, and the officers threatened to break down the door if she did not let them in. Mapp eventually allowed the officers to enter, but she demanded to see a search warrant. The officers did not have a warrant, but they searched the home anyway and found several obscene books and pictures. Mapp was arrested and charged with possessing obscene materials, a crime under Ohio law.
Mapp appealed her conviction, arguing that the search of her home was unconstitutional because it was conducted without a warrant. The case made its way to the Supreme Court, where the Court agreed with Mapp and overturned her conviction.
In its decision, the Court held that the Fourth Amendment applies to state and local governments, not just the federal government. This means that state and local police officers must follow the same rules as federal officers when it comes to searches and seizures. The Court also ruled that evidence obtained through an unconstitutional search cannot be used in a criminal trial. This became known as the "exclusionary rule."
The Mapp v. Ohio decision was a significant victory for civil liberties and has had a lasting impact on criminal procedure in the United States. It established that the Fourth Amendment protects individuals from unreasonable searches and seizures by state and local law enforcement, and it established the exclusionary rule, which prevents the use of illegally obtained evidence in a criminal trial. The case has been cited in numerous subsequent cases involving issues related to the Fourth Amendment and the exclusionary rule.