Which Supreme Court case established the exclusionary rule?

The establishment of the exclusionary rule is a pivotal moment in the history of American criminal procedure, which Mapp v. Ohio accomplished. This case, decided in 1961, applied the exclusionary rule to state courts, affirming that evidence obtained in violation of the Fourth Amendment, which protects against unreasonable searches and seizures, cannot be used in court.

The ruling stemmed from the events surrounding the search of Dollree Mapp’s home, where evidence was obtained without a proper warrant. The Supreme Court held that states are required to follow the exclusionary rule, a principle that had previously only applied to federal courts. This case linked the right to privacy with the legal consequence of excluding illegally obtained evidence, reinforcing the idea that adherence to constitutional protections is critical to the integrity of the judicial system.

Other cases in the options provided—like Miranda v. Arizona, Gideon v. Wainwright, and Brown v. Board of Education—address different legal principles. Miranda established rights regarding self-incrimination and the requirement for police to inform suspects of their rights, Gideon focused on the right to counsel, and Brown challenged racial segregation in public schools. While all are foundational to civil rights and justice, it is Mapp v. Ohio that specifically established