The Fourth Amendment to the United States Constitution is part of the Bill of Rights. It prohibits unreasonable searches and seizures. In addition, it sets requirements for issuing warrants: warrants must be issued by a judge or magistrate, justified by probable cause, supported by oath or affirmation, and must particularly describe the place to be searched and the persons or things to be seized.
Atwater v. Lago Vista, 532 U.S. 318 (2001), was a United States Supreme Court decision which held that a person's Fourth Amendment rights are not violated when the subject is arrested for driving without a seatbelt. The court ruled that such an arrest for a misdemeanor that is punishable only by a fine does not constitute an unreasonable seizure under the Fourth Amendment.
"Stop and identify" statutes are laws in several U.S. states that authorize police to lawfully order people whom they reasonably suspect of committing a crime to state their name. If there is not reasonable suspicion that a person has committed a crime, is committing a crime, or is about to commit a crime, the person is not required to identify themself, even in these states.
Hudson v. Michigan, 547 U.S. 586 (2006), is a United States Supreme Court case in which the Court held that a violation of the Fourth Amendment requirement that police officers knock, announce their presence, and wait a reasonable amount of time before entering a private residence does not require suppression of the evidence obtained in the ensuing search.
Arizona v. Evans, 514 U.S. 1 (1995), was a United States Supreme Court case in which the Court instituted an exclusionary rule exception allowing evidence obtained through a warrantless search to be valid when a police record erroneously indicates the existence of an outstanding warrant due to negligent conduct of a Clerk of Court.
Welsh v. Wisconsin, 466 U.S. 740 (1984), was a 1983 case before the US Supreme Court determining that a warrantless home arrest without exigent circumstances violates the Fourth Amendment protection against unlawful search and seizure.
Arizona v. Gant, 556 U.S. 332 (2009), was a United States Supreme Court decision holding that the Fourth Amendment to the United States Constitution requires law-enforcement officers to demonstrate an actual and continuing threat to their safety posed by an arrestee, or a need to preserve evidence related to the crime of arrest from tampering by the arrestee, in order to justify a warrantless vehicular search incident to arrest conducted after the vehicle's recent occupants have been arrested and secured.
Melendez-Diaz v. Massachusetts, 557 U.S. 305 (2009), is a United States Supreme Court case in which the Court held that it was a violation of the Sixth Amendment right of confrontation for a prosecutor to submit a chemical drug test report without the testimony of the person who performed the test. While the court ruled that the then-common practice of submitting these reports without testimony was unconstitutional, it also held that so called "notice-and-demand" statutes are constitutional. A state would not violate the Constitution through a "notice-and-demand" statute by both putting the defendant on notice that the prosecution would submit a chemical drug test report without the testimony of the scientist and also giving the defendant sufficient time to raise an objection.
Whren v. United States, 517 U.S. 806 (1996), was a unanimous United States Supreme Court decision that "declared that any traffic offense committed by a driver was a legitimate legal basis for a stop."
United States v. Jones, 565 U.S. 400 (2012), was a landmark United States Supreme Court case in which the court held that installing a Global Positioning System (GPS) tracking device on a vehicle and using the device to monitor the vehicle's movements constitutes a search under the Fourth Amendment.
Florence v. Board of Chosen Freeholders, 566 U.S. 318 (2012), was a United States Supreme Court case in which the Court held that officials may strip-search individuals who have been arrested for any crime before admitting the individuals to jail, even if there is no reason to suspect that the individual is carrying contraband.
Florida v. Jardines, 569 U.S. 1 (2013), was a United States Supreme Court case which resulted in the decision that police use of a trained detection dog to sniff for narcotics on the front porch of a private home is a "search" within the meaning of the Fourth Amendment to the United States Constitution, and therefore, without consent, requires both probable cause and a search warrant.
Maryland v. King, 569 U.S. 435 (2013), was a decision of the United States Supreme Court which held that a cheek swab of an arrestee's DNA is comparable to fingerprinting and therefore, a legal police booking procedure that is reasonable under the Fourth Amendment.
Riley v. California, 573 U.S. 373 (2014), is a landmark United States Supreme Court case in which the court ruled that the warrantless search and seizure of the digital contents of a cell phone during an arrest is unconstitutional under the Fourth Amendment.
Heien v. North Carolina, 574 U.S. 54 (2014), was a decision by the United States Supreme Court, ruling that a police officer's reasonable mistake of law can provide the individualized suspicion required by the Fourth Amendment to the United States Constitution to justify a traffic stop. The Court delivered its ruling on December 15, 2014.
Navarette v. California, 572 U.S. 393 (2014), was a case in which the United States Supreme Court clarified when police officers may make arrests or conduct temporary detentions based on information provided by anonymous tips. In 2008, police in California received a 911 call that a pickup truck was driving recklessly along a rural highway. Officers spotted a truck matching the description provided in the 911 call and followed the truck for five minutes, but did not observe any suspicious behavior. Nevertheless, officers conducted a traffic stop and discovered 30 pounds (14 kg) of marijuana in the truck. At trial, the occupants of the car argued that the traffic stop violated the Fourth Amendment of the United States Constitution, because the tip was unreliable, and officers did not personally observe criminal activity. Writing for a majority of the Court, Justice Clarence Thomas held that the 911 call was reliable, and that officers need not personally observe criminal activity when acting upon information provided by an anonymous 911 call.
Collins v. Virginia, No. 16-1027, 584 U.S. ___ (2018), was a case before the US Supreme Court involving search and seizure. At issue was whether the Fourth Amendment's motor vehicle exception permits a police officer uninvited and without a warrant to enter private property, approach a house, and search a vehicle parked a few feet from the house that is otherwise visible from off the property. In an 8–1 judgement, the Supreme Court ruled that the automobile exception does not apply to vehicles parked within the home or the curtilage of a private homeowner.
Nieves v. Bartlett, 587 U.S. ___ (2019), was a civil rights case in which the Supreme Court of the United States decided that probable cause should generally defeat a retaliatory arrest claim brought under the First Amendment, unless officers under the circumstances would typically exercise their discretion not to make an arrest.
Mitchell v. Wisconsin, 588 U.S. ___ (2019), is a United States Supreme Court case in which the Court held that "when a driver is unconscious and cannot be given a breath test, the exigent-circumstances doctrine generally permits a blood test without a warrant."
Johnson v. United States, 333 U.S. 10 (1948), was a significant United States Supreme Court decision addressing search warrants and the Fourth Amendment. In this case, where federal agents had probable cause to search a hotel room but did not obtain a warrant, the Court declared the search was "unreasonable."
