Mapp v. Ohio

Following is the case brief for Mapp v. Ohio, United States Supreme Court, (1961)

Case Summary of Mapp v. Ohio:

  • Mapp’s home was searched absent a warrant.
  • The search yielded the discovery of material classified as “obscene” under Ohio state law.
  • The Supreme Court held that evidence obtained from an unreasonable search and seizure could not be used against the accused in criminal state court.
  • The court made a point of noting the inconsistency of state courts being permitted to introduce evidence that the federal courts have held to be a violation since both the state and federal government follow the U.S. Constitution.

Mapp v. Ohio Case Brief

Statement of the Facts:

In response to a tip that a suspect was hiding in Mapp’s home, police forcibly entered without consent. After Mapp demanded the search warrant, an officer showed her a paper alleged to be a warrant. Mapp took the warrant and police responded by physically retrieving it from her. As a result of the search, books and photos belonging to Mapp were introduced into evidence. Mapp was convicted for possessing lewd and obscene material under Ohio law despite the fact no evidence was offered to show that police obtained a warrant to search her home.

Procedural History:

Mapp appealed the conviction to the Ohio Supreme Court, which sustained the conviction although it acknowledged a reasonable reversal argument since the evidence was obtained in an improper manner. Mapp then appealed to the United States Supreme Court stating the conviction was the result of unreasonable search and seizure.

Issues and Holding:

Whether evidence obtained through an unreasonable search and seizure is admissible against a defendant in state court for state offenses? No.


No, Reversed and Remanded back to the trial court.

Rule of Law or Legal Principle Applied:

In state criminal proceedings, any evidence obtained through an unreasonable search and seizure is inadmissible and violates the Fourth Amendment.


When Evidence is illegally obtained in violation of the constitution, it is inadmissible in state court.  Any evidence obtained when the government invades an individual’s privacy right, violates both the Fourth and Fifth Amendment.  As a result, the evidence received cannot be used without violating a constitutional right (Boyd v. United States, 116 U.S. 616 (1886)).

Using this as precedent, the Court in Weeks v. United States, 232 U.S. 383 (1914) held such evidence obtained by an unreasonable search and seizure was inadmissible against a defendant in federal court since excluding the evidence was the only way to uphold the Fourth Amendment rights.

However, the Court in Wolf v. Colorado, 338 U.S. 25 (1949) held that although the states incorporated  the Fourth Amendment through the Due Process Clause of the 14th Amendment, excluding the evidence was not “an essential ingredient of the right.”

Here, the Court pointed out the flaw in having evidence that is prohibited in federal court used in states court when both should be operating under the same amendments. The Court held it was time to overrule Wolf v. Colorado, establishing precedent that the federal exclusionary rule now applies to the states through the application of the 14th Amendment.

Concurring/Dissenting opinions:

Concurrence (Black):

Black states the Fourth Amendment does not specifically mandate exclusion of illegally seized evidence. However, when combined with the Fifth Amendment (right against incrimination) a constitutional right emerges requiring the exclusion of illegally seized evidence in criminal trials.

Dissent (Harlan):

Overturning Wolf v. Colorado was inappropriate and overreaching. The doctrine of stare decisis was violated when the Court states the Fourth Amendment applies to the states through the 14th Amendment. The only constitutional issue in this case is related to Mapp’s First Amendment right’s regarding free expression and whether it conflicts with Ohio’s obscenity law.


Mapp v. Ohio extended the exclusionary rule, which was then being applied to the federal courts, to the state courts. Application of the Fourth Amendment protection against the introduction of evidence obtained from an illegal search and seizure is applied to the states through the 14th Amendment.

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