What does Mapp v. Ohio establish about evidence obtained illegally?

Mapp v. Ohio is a landmark case that established the exclusionary rule at the state level, expanding upon the Fourth Amendment protections against unreasonable searches and seizures. The ruling affirmed that evidence obtained through illegal searches and seizures cannot be used in state court.

Prior to this decision, the exclusionary rule was primarily applied at the federal level, and states had the discretion to allow illegally obtained evidence. However, the Supreme Court's ruling in Mapp v. Ohio mandated that all states must adhere to the exclusionary rule, thus ensuring that the protections offered by the Fourth Amendment are uniformly applied across both federal and state courts. This foundational principle promotes fairness in the legal process and deters law enforcement from conducting unlawful searches, as any evidence obtained in violation of a person's constitutional rights would be deemed inadmissible.

In summary, Mapp v. Ohio firmly established that illegally obtained evidence is inadmissible in state court, reinforcing the importance of lawful procedures in the collection of evidence.