What amendment did the court use to reach the amendment decision that the supreme court ruled that a citizen of US cannot be convicted using evidence that was obtained illegally?

The Supreme Court used the Fourth Amendment, which protects against unreasonable searches and seizures, to reach its decision regarding the use of illegally obtained evidence. This principle was established in the landmark case Mapp v. Ohio (1961), where the Court ruled that evidence obtained in violation of the Fourth Amendment cannot be used in state courts. The ruling reinforced the exclusionary rule, ensuring that citizens are protected from unlawful evidence in criminal prosecutions.