Smith v. Maryland

Following is the case brief for Smith v. Maryland, United States Supreme Court, (1978)

Case summary for Smith v. Maryland:

  • Smith was arrested and charged with robbing Patricia McDonough.
  • Evidence, which was obtained by a pen registry absent a warrant, was introduced that Smith called McDonough from his home despite Smith’s objections.
  • Smith appealed claiming he had an expectation of privacy in the phone records and his Fourth Amendment rights were violated.
  • The Court held there is no reasonable expectation of privacy in phone numbers dialed by an individual from their home.

Case Brief for Smith v. Maryland

Statement of the facts:

After committing a robbery, Michael Lee Smith continued to harass his victim by placing threatening and obscene phone calls to her home days after the event took place. Police later spotted Smith, driving the same Monte Carlo described to the police. Smith was arrested. Absent a warrant, the police ordered a telephone company to installed a pen register at its central office to record the numbers dialed from the petitioner’s home telephone. Smith was tried and found guilty of committing a robbery. Contrary to his objections, the tape evidencing that Smith called the robbery victim was introduced before the court.  In response, Smith appealed.

Procedural History:

Smith appealed to the Maryland court of special appeals. In response, the court issued a writ of certiorari to the intermediate court. This intermediate court of appeals affirmed the judgment. Smith then appealed to the Supreme Court of the United States.

Rule of Law or Legal Principle Applied:

Under the Fourth Amendment, a person is protected against unreasonable searches and seizures when they have a subjective and reasonable expectation of privacy.

Issue and Holding:

Will an individual have a reasonable expectation of privacy in the numbers he calls from his own home? No.


The Court affirmed the lower court’s judgment.


The Court held there is no reasonable expectation of privacy in phone numbers dialed by an individual. As a result, the evidence obtained through the pen register was properly ruled as admissible.

The fact that a phone company keeps a records of outgoing calls is public knowledge, so the Court held that it follows when an individual places a call, they are voluntarily making public who they call. Smith only had a reasonable expectation that the contents of his conversation would be private. The same cannot be said of the number he called remaining out of public record.

The Court held that even if Smith did in fact believe he had an expectation of privacy in the number dialed, the expectation was not reasonable. In addition, the use of a pen register to extract public information does not constitute a Fourth Amendment search.

Concurring or Dissenting opinion:

Dissenting (Marshall):

Presuming people know phone companies keep records of their outgoing calls, voluntary disclosure to a third party does not equate to assuming the risk the information will be relayed to the police.

Dissenting (Stewart):

The Majority is incorrect in ruling that the Fourth Amendment does not apply to phone numbers dialed in the privacy of one’s home. This is because the information comes from places where an individual possesses a reasonable expectation of privacy, and revealing who the individual speaks with reveals intimate details regarding their life.


This case addresses that there is no expectation of privacy in the list of outgoing calls made from an individual’s home.

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