Supreme Court Decisions Mapp v. Ohio

Mapp v. Ohio

Mapp v. Ohio

Mapp v. Ohio is a landmark U.S. Supreme Court case that established the exclusionary rule in criminal trials. The case originated in 1957 when Cleveland police officers forcibly entered the home of Dollree Mapp looking for a bombing suspect. Mapp refused them entry as she had no knowledge of the suspect’s whereabouts and they left. Three hours later, they returned and gained entry without a warrant and found pornographic materials.

Mapp was charged with possession of these materials, but her lawyer argued that the evidence was obtained through an illegal search and should be excluded from the trial under the Fourth Amendment. The case ultimately reached the Supreme Court, which ruled in favor of Mapp and established the exclusionary rule.

The Court held that evidence obtained through a violation of the Fourth Amendment’s prohibition against unreasonable searches and seizures could not be used in criminal trials. This decision was based upon the principle that excluding illegally obtained evidence would disincentivize law enforcement from engaging in unconstitutional behavior.

Mapp v. Ohio was a significant case that had far-reaching implications for criminal law enforcement across the United States. The decision forced law enforcement officials to conduct searches in accordance with the Fourth Amendment, which protected individuals from unreasonable searches and seizures. Additionally, it empowered individuals to challenge the admissibility of evidence obtained through illegal searches, and the exclusionary rule became an important tool for criminal defense attorneys to protect the rights of their clients.

Moreover, this landmark case underlined the need for the courts to protect individual civil liberties against the powers of the state. It was a victory for civil rights and the principle of equal justice under the law. Mapp v. Ohio was a critical moment in American legal history, and the decision has continued to influence the practice of criminal law in the United States.

Despite the case’s importance and impact on both the legal system and society, it has also been subject to much criticism over the years. Some critics argue that the exclusionary rule allows guilty individuals to go free, while others assert that it does not go far enough in curtailing police misconduct.

In conclusion, Mapp v. Ohio was a vital case that established the exclusionary rule and redefined the scope of Fourth Amendment rights. The decision was significant in protecting individual civil liberties against unconstitutional actions by law enforcement, and it remains an important part of American legal history.


Mapp v. Ohio (1961) was a landmark the United States Supreme Court case regarding the Fourth Amendment of the United States Constitution as it relates to criminal procedure. The Court held that evidence that was obtained in violation of the Fourth Amendment could not be used against someone in State or Federal court.

The Fourth Amendment protects the rights of people from “unreasonable searches and seizures”, as well as ensures that no warrants are issued without probable cause. Mapp v. Ohio was the first time this Amendment was applied to criminal procedure in State courts.

A Cleveland, Ohio woman, Dollree Mapp, was suspected of harboring a fugitive in her home. Police officers arrived at her home and demanded entrance. When she refused, they forcibly broke down her door and entered the premises. Mapp requested a search warrant from the officers who presented a piece of paper they claimed was a valid search warrant but did not allow her to view it. Upon searching the entire house, the officers did not find a fugitive. Instead, they discovered a trunk containing lewd photographs and books.

Mapp was arrested based on the violation of an Ohio law banning obscene material. The evidence discovered by police in her home was presented and used against her in court. In Mapp v. Ohio, the police officers never actually presented a search warrant to the court. Mapp was convicted and appealed this decision to the Supreme Court of the United States.

Although two previous Supreme Court cases regarding criminal procedure had found that evidence obtained illegally could not be used against the defendant in court, this had never been applied in State courts before Mapp v. Ohio. It was not until this landmark case that this exclusionary rule began to be enforced in criminal procedure. This case was decided on a 6-3 vote.

In the majority opinion written by Justice Thomas Clark, the Court held that the exclusionary rule also applies to State courts. The Court used the rights of the Fourth Amendment that protect against unreasonable searches, as well as the Due Process Clause of the Fourteenth Amendment. This Clause protects citizens from the loss of liberties without due process of the law.

Justice Clark added to the decision by saying that it does not in any way permit criminals to break the law simply because of the police officer’s error in criminal procedure. He observed that the exclusionary rule is imminent in both these Amendments and that the Government must abide by its own laws.

Another concurring Justice wrote that this decision of the Court was also based on the Fifth Amendment of the Constitution. The Fourth Amendment’s protection against unreasonable search and seizure, he claimed, was not binding enough to deny the use of illegally obtained evidence from being used to convict a criminal. However, in combination with the Fifth Amendment, which protects against self-incrimination, the use of this evidence in criminal procedure is unconstitutional. Mapp v. Ohio was influential in providing stricter enforcement of the exclusionary rules, as well as extending this policy to use in State courts.