Which landmark case established the exclusionary rule for state cases?

The landmark case that established the exclusionary rule for state cases is Mapp v. Ohio. This ruling was significant as it extended the exclusionary rule, which previously applied only to federal law enforcement, to state courts.

In Mapp v. Ohio, the Supreme Court determined that evidence obtained in violation of the Fourth Amendment, which protects against unreasonable searches and seizures, cannot be used in state criminal prosecutions. This decision reinforced the right to privacy and established a critical precedent ensuring that individuals cannot be convicted based on illegally obtained evidence, thereby reinforcing the importance of constitutional protections at both federal and state levels. This outcome was instrumental in shaping the balance between law enforcement practices and the rights of individuals under the Constitution.