Katz v. U.S.(1967)


U.S. District Court convicted Katz of interstate betting and fined him $50

U.S. Court of Appeals affirmed

Katz petitioned U.S. Supreme Court for certiorari

U.S. Supreme Court granted certiorari and reversed


During February, FBI observed Katz enter one of a bank of 3 public telephone booths at certain times almost every day, close the door, pay his toll, and talk.

FBI put a microphone and recorded to the microphone on top of two of the booths; phone company put the third “out of order.”

FBI turned on the mike and recorder only when Katz was approaching and in the booth between February 19 to February 25, 1965

Katz went into the booth, closed the door, put money in the slot, and the FBI heard Katz make bets and get betting information.

FBI heard only Katz not the other party

FBI transcribed Katz’s end of conversation

Question (Issue)

Was listening and recording Katz’s end of the conversation a search? Yes





Two-pronged privacy test used to decide whether government action is a search

Subjective prong. Actual expectation of privacy

Objective prong. Reasonable expectation of privacy (expectation that society’s prepared to recognize)

4th amendment protects people not places

Knowing exposure (wherever it takes place) is not protected

What you “seek to preserve as private” (wherever it is) may be protected if society is prepared to recognize it as private)

Privacy test applied to facts

Subjective prong: When Katz went into the booth, shut the door, and paid his toll “he sought to exclude not the “intruding eye” but the “uninvited ear.”

Objective prong: “he is entitled to assume that the words he utters into the mouthpiece will not be broadcast to the world. To read the Constitution more narrowly is to ignore the vital role that the public telephone booth has come to play in private conversation.”


“Search” in the 4th amendment doesn’t include electronic eavesdropping because founders knew what eavesdropping was and they left it to private law.

It’s not the Court’s role to rewrite the 4th amendment to “bring it into harmony with the times” in order to reach a result that a lot of people think is good.

“The 4th amendment was aimed directly at the abhorred practice of breaking in, ransacking, and searching homes and other buildings, and seizing people’s belongings without warrants by magistrates.”

“I will not distort the the words of the Amendment in order to ‘keep the Constitution up to date’ or ‘bring it into harmony with the times.’ It was never meant that this Court have such power, which in effect would make us a continuously functioning constitutional convention.”