Amendment IV of the United States Constitution
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Ratified December 15, 1791
Mapp v. Ohio (1961)
The Supreme Court held that all evidence obtained by an illegal search and seizure violating the Fourth Amendment is inadmissible in a criminal trial in a state court to be used against the accused. Learn More
Katz v. United States (1967)
The Supreme Court held that 4th Amendment protection against unreasonable searches and seizures applies to where one would have a reasonable expectation of privacy, including a private conversation on a public pay phone. Learn More
Terry v. Ohio (1967)
The Supreme Court held that it is not an unreasonable search and seizure in violation of the 4th Amendment for a police officer with a reasonable suspicion about an individual’s behavior may stop that individual to investigate and conduct a limited search or “frisk” that individual if the officer reasonably believes the individual might be armed in order to protect the safety of the officer during the investigation. Learn More
New Jersey v. T.L.O. (1985)
The Supreme Court held that the 4th Amendment protection against unreasonable searches and seizures applies in public schools and to public school officials, but warrantless searches are permitted and probable cause is not required if the search is reasonable and there is reasonable suspicion of violation of the law or school rules. “Such a search will be permissible in its scope when the measures adopted are reasonably related to the objectives of the search and not excessively intrusive in light of the age and sex of the student and the nature of the infraction.” Learn More
- Fourth Amendment Timeline, posted by the Annenberg Classroom
- Fourth Amendment Search and Seizure, in Constitution Annotated, produced by the Congressional Research Service
- Mapp v. Ohio (1961), posted by C-SPAN’s Landmark Cases
“Fourth Amendment: Search and Seizure,” Classroom Resources, in Education, posted by the National Constitution Center
“What is a Reasonable Expectation of Privacy?” includes handouts and activities, posted by the Bill of Rights Institute
“New Jersey v. T.L.O.” includes materials, hypothetical scenarios for analysis, and discussion questions, in Educational Resources, posted by U.S. Courts
Search and Seizure: Mapp v. Ohio, from the Annenberg Classroom. This video examines the Fourth Amendment protections against unreasonable searches and seizures and the landmark Supreme Court decision in Mapp v. Ohio (1961), which held that evidence obtained in an illegal search and seizure could not be admitted in a criminal trial in a state court to be used against the accused. Here is a lesson plan to accompany this video.