Mapp v. Ohio Precedents:

1. Wolf v. Colorado (1949): The Court held that in a prosecution in a State court for a State crime, the Fourteenth Amendment does not forbid the admission of evidence obtained by an unreasonable search and seizure.
2. Olmstead v. U.S. (1928): The Court forbade the introduction of evidence if obtained by government officers through a violation of the Fourth Amendment.
3. Palko v. Connecticut (1937): The security of ones privacy against arbitrary intrusion by the police is implicit in the concept of ordered liberty and as susch enforceable against the States through the Due Process Clause.
4. Weeks v. U.S. (1914): In a federal prosecution the Fourth Amendment bars the use of evidence secured through an illegal search.