Lesson 4 of 10
The Fourth Amendment: Searches, Seizures and Warrants
Probable cause, particular warrants, and your phone.
The 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.
That the people shall be secure in their persons, houses, papers and possessions, from unreasonable searches and seizures; and that general warrants, whereby an officer may be commanded to search suspected places, without evidence of the fact committed, or to seize any person or persons not named, whose offences are not particularly described and supported by evidence, are dangerous to liberty, and ought not to be granted.
The people shall be secure in their persons, papers, homes and effects, from unreasonable searches and seizures; and no warrant to search any place or seize any person or things shall issue without describing the place to be searched, or the person or thing to be seized, as near as may be, nor without probable cause, supported by oath or affirmation reduced to writing.
What it plainly means
You have a right to be secure in your person, house, papers and belongings against unreasonable searches and seizures. A warrant requires probable cause, sworn to under oath, and it must "particularly" describe the place to be searched and the persons or things to be seized.
History and the Founders' intent
In 1761 Boston lawyer James Otis argued against the "writs of assistance," open-ended warrants that let customs officers search any home or ship for smuggled goods. John Adams later wrote that "Then and there the child Independence was born." (10 Works of John Adams 247-248 (C. Adams ed. 1856), quoted in Riley v. California.) In England, the cases of Entick v. Carrington (1765) and Wilkes v. Wood (1763) condemned general warrants used against government critics. The Framers required that warrants be specific and sworn, so a neutral magistrate, not the officer in the field, decides whether a search is justified.
Key Supreme Court cases
- Mapp v. Ohio, 367 U.S. 643 (1961): evidence obtained by an unconstitutional search may not be used in state prosecutions (the exclusionary rule).
- Katz v. United States, 389 U.S. 347 (1967): the Amendment "protects people, not places"; a wiretap of a phone booth was a search.
- Terry v. Ohio, 392 U.S. 1 (1968): police may briefly stop and frisk on reasonable suspicion that a person is armed and involved in crime.
- United States v. Jones, 565 U.S. 400 (2012): attaching a GPS tracker to a car is a search, reasoning from the original trespass understanding.
- Riley v. California, 573 U.S. 373 (2014): police generally need a warrant to search a phone seized at arrest.
- Carpenter v. United States, 585 U.S. 296 (2018): the government generally needs a warrant to obtain historical cell-site location records from a phone company (the Court held that obtaining seven days or more of such records is a search).
What it means for you today
You do not have to consent to a search; if officers ask, you may calmly say you do not consent. If they have a warrant, you may ask to see it. Your phone's contents and your long-term location history are protected. Tennessee's Article I, Section 7 condemns general warrants in so many words, and Colorado's Article II, Section 7 requires the supporting oath to be "reduced to writing."
Check your understanding
This lesson is educational and is not legal advice. Laws and procedures change; confirm current rules with the official sources linked above.