Katz v. United States: Case Brief

Instructor: Brittany McKenna

Brittany is a licensed attorney who specializes in criminal law, legal writing, and appellate practice and procedure.

The Supreme Court's landmark Katz v. United States decision introduced a new test for Fourth Amendment searches and seizures. In this lesson, you will be introduced to the facts of the case, as well as the Supreme Court's analysis and legal conclusions.

Questions Presented in Katz v. United States

Imagine you are talking to your significant other on the telephone. You talk about how your day is going, about how your coworker was really getting on your nerves during a meeting, and about how you need to stop by the grocery on your way home. Now imagine that a complete stranger is listening in on that very conversation. Creepy, right?

Even in the case of the most boring and mundane subject matter, you expect that your private conversations are actually private.

In the landmark Katz v. United States case, the Supreme Court of the United States introduced a new test for determining when private conversations in public places are protected by constitutional principles. While the Fourth Amendment of the United States Constitution protects against illegal searches and seizures and courts have interpreted this right to extend to police searches, in Katz v. United States, the Supreme Court was asked the following questions in relation to the protection under the Fourth Amendment:

  • Does the Fourth Amendment's right to privacy extend to public places?
  • Does an actual, physical 'intrusion' constitute a search a seizure?

Facts of the Case

Agents with the Federal Bureau of Investigation became suspicious that Los Angeles resident Charles Katz was operating an illegal gambling operation out of a public phone booth. The FBI agents attached an electronic eavesdropping device (a wiretap) to the outside of the phone booth and waited for Katz to place a call. As they listened to Katz's conversation, they concluded that Katz was indeed transmitting gambling wagers from Los Angeles to Miami and Boston via the public phone line.

Katz was arrested and was convicted based on the evidence of the illegal phone wagers. He appealed his convictions on the grounds that the evidence was illegally obtained without a warrant in violation of his Fourth Amendment privacy rights.

The Supreme Court's Holding and Analysis

In reaching its decision, the Supreme Court reasoned that the Fourth Amendment applies to people, not places. Based on this rationale, the fact that a person is having a private conversation in a public place does not strip away that person's Fourth Amendment right to privacy and held that a private conversation is protected under the Fourth Amendment so long as the speaker has a reasonable expectation of privacy where the conversation takes place, which became a new Fourth Amendment test: reasonable expectation of privacy.

Any invasion of that right constitutes a search and seizure, regardless of the 'level' of intrusion. The Supreme Court concluded that the use of a wiretap constituted a search and seizure . Therefore, the fact that the FBI placed the wiretap outside of the phone booth was irrelevant in the context of Fourth Amendment protections.

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