Which landmark case established that evidence obtained illegally cannot be used in court?

The landmark case that established that evidence obtained illegally cannot be used in court is Mapp v. Ohio. This 1961 Supreme Court decision extended the exclusionary rule, which was originally applied only to federal courts, to state courts as well. The ruling was based on the Fourth Amendment, which protects citizens against unreasonable searches and seizures. The case involved police officers who unlawfully entered the home of Dollree Mapp without a warrant and found obscene materials, which they used to convict her. The Supreme Court held that evidence obtained in violation of the Fourth Amendment is inadmissible in court, reinforcing the principle that individuals have a right to privacy and protection from unlawful governmental intrusion. This case is significant in upholding the integrity of the judicial system by ensuring that courts do not condone illegal police conduct.