Katz v. United States

Investigations to obtain information about a suspect's private activities, even if those activities are conducted in public places or are obtained via electronic media or means, are subject to the same standards of judicial process as searches of a suspect's private property.

Charles Katz was convicted of transmitting gambling information by telephone from Los Angeles, California to Miami, Florida; and Boston, Massachusetts. At his trial in U.S. District Court for the Southern District of California, Katz objected to the use of information obtained by an electronic surveillance device placed on a public phone he used to transact business. Following his conviction, Katz's case was appealed to the Court of Appeals for the Ninth Circuit, where the district court's decision was upheld.

Katz's appeal was denied on the basis of the precedent established in the case of Olmstead v. United States in 1928. In this case, a group of individuals were convicted in U.S. district court of illegally possessing, transporting, and importing intoxicating liquors during Prohibition. Government evidence leading to these convictions was obtained by wiretapping the plaintiffs' telephones. The plaintiffs argued that the evidence was obtained in violation of the Fourth Amendment prohibition of unreasonable search and seizure, and appealed their case to the U.S. Supreme Court where their convictions were upheld. At the time, Chief Justice William Howard Taft delivered the Court's opinion, stating that the language of the Fourth Amendment " . . . can not be extended and expanded to include telephone wires reaching the whole world from the defendant's house or office. The intervening wires are not part of his house or office, any more than are the highways along which they are stretched . . . " He clarified his position by adding that a defendant's Fourth Amendment rights will not be violated " . . . unless there has been an official search and seizure of his person or such a seizure of his papers or his tangible material effects or an actual physical invasion of his house `or curtilage' for the purpose of making a seizure." In Katz's case, law enforcement agents had scrupulously adhered to existing standards for applying wiretaps, but did not seek judicial approval (a warrant) for conducting a search and did not report the results of their search to a magistrate.

In seeking to persuade the Court to overturn Olmstead v. United States, Katz's attorneys argued that a public telephone should be considered a constitutionally protected area and, as such, that the surreptitious recording of conversations held in a phone booth would violate the right to privacy of the booth's user. They also raised the question of whether actual " . . . physical penetration of a constitutionally protected area is necessary before a search and seizure can be said to violate the Fourth Amendment . . . " The government's attorneys argued that the law enforcement agents monitoring Katz acted as they did due to their understanding of Olmstead, and that in any case the wiretapping of a public telephone should be viewed as exempt from advance authorization by a magistrate.

Although the Court did not agree with the arguments put forward by Katz's attorneys, they did rule to overturn his conviction with Justice Black the lone dissenter. Justice Stewart delivered the Court's opinion, holding that the "Fourth Amendment protects people, not places," and therefore the fact that Katz's conversations occurred in a public phone booth was irrelevant. He further offered that what a person " . . . seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected . . . wherever a man may be, he is entitled to know that he will remain free from unreasonable searches and seizures." The Court had already stated, in an earlier case, Beck v. Ohio, that omission of judicial authorization of a proposed search or seizure "bypasses the safeguards provided by an objective predetermination of probable cause, and substitutes instead the far less reliable procedure of an after-the-event justification for the . . . search, too likely to be subtly influenced by the familiar shortcomings of hindsight judgement."

Katz removed many constitutional questions raised by Olmstead, which had seemed to draw distinctions between places and media with regard to the applicability of the Fourth Amendment. After Katz, it was clear that the Fourth Amendment prohibition of unreasonable search and seizure was equally applicable to physical searches and monitoring of electronic media.