Founding Values

Amendment IV

Search and Seizure

Ratified December 15, 1791

The Fourth Amendment requires government searches and seizures to be reasonable, and most warrants to be supported by probable cause with particularity. Katz v. United States (1967) established the 'reasonable expectation of privacy' standard; Carpenter (2018) extended this to digital cell-site location data.

Bill of RightsPrivacySearch and SeizureFourth Amendment
Passed by Congress September 25, 1789Ratified December 15, 1791

Full Text

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.

Annotated Version

The Bill of Rights document includes phrase highlights and court case references for this amendment.