What did the Supreme Court decide in Mapp v Ohio regarding the Fourth Amendment?

The ruling in Mapp v. Ohio extended the exclusionary rule to state courts, which means that any evidence obtained in violation of the Fourth Amendment cannot be used in a trial. The Supreme Court determined that the Fourth Amendment protects against unreasonable searches and seizures, and thus, any evidence gathered through such means is considered tainted. This landmark decision highlighted the necessity for law enforcement to adhere to constitutional protections, ensuring that individuals' rights are upheld in both federal and state jurisdictions. The ruling is significant because it emphasized that the integrity of the legal process relies on the compliance with constitutional standards, thereby reinforcing the principle that unlawful searches do not yield valid evidence in a court of law.