Olmstead v. United States

Olmstead v. United States, 277 U.S. 438 (1928), was a decision of the Supreme Court of the United States, on the matter of whether wiretapping of private telephone conversations, obtained by federal agents without a search warrant and subsequently used as evidence, constituted a violation of the target’s rights under the Fourth and Fifth Amendments. In a 5–4 decision, the Court held that the Constitutional rights of a wiretapping target have not been violated. This decision was overturned by Katz v. United States in 1967. Background Seizure of evidence Until 1914, the American judicial system largely followed the precepts of English common law when it came to matters pertaining to the validity of introducing evidence in criminal trials. In most cases, the general philosophy was that the process to obtain the evidence had little to do with admissibility in court. The only limiting factor was that police agents could not break the law when seizing the evidence. In 1914, in the landmark case Weeks v. United States, the Supreme Court held unanimously that illegal seizure of items from a private residence was a violation of the Fourth Amendment, and established the exclusionary rule that prohibits admission of illegally obtained evidence in federal courts. Because the Bill of Rights did not at the time extend to the states, such a prohibition applied only to federal agents and covered only federal trials. It was not until the Supreme Court ruling in Mapp v. Ohio (1961) that the exclusionary rule was extended to state law enforcement officers as well.