Katz v. United States

Following is the case brief for Katz v. United States, 389 U.S. 347 (1967).

Case Summary of Katz v. United States:

  • The FBI, using a device attached to the outside of a telephone booth, recorded petitioner’s phone conversations while in the enclosed booth.
  • Petitioner was subsequently convicted of making wagering calls in violation of federal law. The FBI’s recordings were used as evidence at the trial.
  • On appeal, the Court of Appeals affirmed the conviction. The Court of Appeals held that petitioner’s Fourth Amendment rights were not violated because there was no physical intrusion into the phone booth.
  • The Supreme Court disagreed, holding that petitioner’s Fourth Amendment rights were violated because he had a reasonable expectation of privacy in the phone booth.

Katz v. United States Case Brief

Statement of the Facts:

The petitioner used a telephone booth to make wagering calls across state lines in violation of federal law. FBI agents, who were surveilling petitioner for illegal gambling activity, placed a listening device on top of the telephone booth and recorded petitioner’s end of his phone calls. Those recordings were used at petitioner’s trial, over petitioner’s objection. Petitioner was ultimately convicted. The Ninth Circuit Court of Appeals affirmed the conviction, finding that petitioner’s Fourth Amendment rights were not violated because the FBI did not physically enter the telephone booth.

Procedural History:

Petitioner was convicted in Federal District Court. The Ninth Circuit Court of Appeals affirmed the conviction.  Petitioner appealed to the U.S. Supreme Court. The Supreme Court granted certiorari.

Issue and Holding:

Is electronic eavesdropping on a person’s conversation in a telephone booth a “search and seizure” within the meaning of the Fourth Amendment?  Yes.


The Court of Appeals decision is reversed.

Rule of Law or Legal Principle Applied:

If a person has a reasonable expectation of privacy in a conversation, that conversation is protected by the Fourth Amendment and cannot be recorded by the Government without a warrant.


First, the Fourth Amendment covers the “seizure” of oral statements as well as tangible items. The recording of petitioner’s side of his phone conversations was, therefore, a seizure under the Fourth Amendment.

Second, both parties in the case improperly focused on whether the phone booth was a “constitutionally protected area.” The Fourth Amendment’s protections extent to people, not places. Accordingly, the question of whether the phone booth is “constitutionally protected” is not relevant. The relevant inquiry is whether a person can justifiably rely on his privacy in a certain situation. Here, petitioner’s use of a phone booth, with the door closed, indicates his expectation of privacy in his conversation.

The Government, therefore, could not record petitioner’s conversation without first getting a warrant.

Concurring and Dissenting Opinions:

Concurring (Douglas):

Justice Douglas wrote separately to refute Justice White’s concurring opinion. Justice Douglas found that the Fourth Amendment applies uniformly to any electronic eavesdropping, whether in routine law enforcement matters or matters of national security.

Concurring (Harlan):

Justice Harlan wrote separately to clarify the majority’s holding that the Fourth Amendment applies when a person has (i) an expectation of privacy that (ii) society considers objectively reasonable. Petitioner’s use of the phone booth with the door closed demonstrates his reasonable expectation of privacy in the present case. The Court’s opinion should not be read to mean a recorded conversation in a telephone booth will always require a warrant.

Concurring (White):

Justice White agreed with the Court’s opinion, but noted that a warrant should not be required if the President or Attorney General order a wiretap for reasons of national security.

Dissenting (Black):

Justice Black found that the recording of oral statements is not a “seizure” under the Fourth Amendment. The Fourth Amendment speaks in terms of “tangible” items, not oral statements. Thus, the Court improperly expanded the terms of the Fourth Amendment to cover a more general notion of privacy.


Largely based on the test provided in Justice Harlan’s concurrence, Katz v. United States is well known for establishing Fourth Amendment protection for statements made when a person has a “reasonable expectation of privacy,” regardless of locale. Thus, the Fourth Amendment is implicated when the Government intrudes on a person’s reasonable expectation of privacy.

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