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.
In United States criminal law, probable cause is the standard by which police authorities have reason to obtain a warrant for the arrest of a suspected criminal or the issuing of a search warrant. It is also the standard by which grand juries issue criminal indictments. The principle behind the standard is to limit the power of authorities to perform random or abusive searches, and to promote lawful evidence gathering and procedural form during criminal arrest and prosecution. The standard also applies to personal or property searches.
Terry v. Ohio, 392 U.S. 1 (1968), was a landmark decision of the Supreme Court of the United States in which the Court ruled that the Fourth Amendment's prohibition on unreasonable searches and seizures is not violated when a police officer stops a suspect on the street and frisks him or her without probable cause to arrest, if the police officer has a reasonable suspicion that the person has committed, is committing, or is about to commit a crime and has a reasonable belief that the person "may be armed and presently dangerous."
A Terry stop in the United States allows the police to briefly detain a person based on reasonable suspicion of involvement in criminal activity. Reasonable suspicion is a lower standard than probable cause which is needed for arrest. When police stop and search a pedestrian, this is commonly known as a stop and frisk. When police stop an automobile, this is known as a traffic stop. If the police stop a motor vehicle on minor infringements in order to investigate other suspected criminal activity, this is known as a pretextual stop. Additional rules apply to stops that occur on a bus.
In the United States, the exclusionary rule is a legal rule, based on constitutional law, that prevents evidence collected or analyzed in violation of the defendant's constitutional rights from being used in a court of law. This may be considered an example of a prophylactic rule formulated by the judiciary in order to protect a constitutional right. The exclusionary rule may also, in some circumstances at least, be considered to follow directly from the constitutional language, such as the Fifth Amendment's command that no person "shall be compelled in any criminal case to be a witness against himself" and that no person "shall be deprived of life, liberty or property without due process of law."
United States v. Place, 462 U.S. 696 (1983), was a decision by the Supreme Court of the United States which held that a sniff of luggage in a public place, by a police dog specially trained to detect the odor of narcotics, was not a "search" under the meaning of the Fourth Amendment to the United States Constitution. The Court reasoned that the sniff of a dog is sui generis, intended to disclose only the presence or absence of narcotics. Because a dog sniff is such a limited test, the Court carved out this exception from the broad category of "searches" for which a warrant is generally required.
United States v. Matlock, 415 U.S. 164 (1974), was a Supreme Court of the United States case in which the Court ruled that the Fourth Amendment prohibition on unreasonable searches and seizures was not violated when the police obtained voluntary consent from a third party who possessed common authority over the premises sought to be searched. The ruling of the court established the "co-occupant consent rule," which was later explained by Illinois v. Rodriguez, 497 U.S. 177 (1990) and distinguished later by Georgia v. Randolph (2006), in which the court held that a third party could not consent over the objections of a present co-occupant, and Fernandez v. California (2014), where the court held when the objecting co-resident is removed for objectively reasonable purposes, the remaining resident may validly consent to search.
Illinois v. Rodriguez, 497 U.S. 177 (1990), is a U.S. Supreme Court case dealing with the issue of whether a warrantless search conducted pursuant to third party consent violates the Fourth Amendment when the third party does not actually possess common authority over the premises.
Illinois v. Caballes, 543 U.S. 405 (2005), was a United States Supreme Court case in which the Court held that the Fourth Amendment is not violated when the use of a drug-sniffing dog during a routine traffic stop does not unreasonably prolong the length of the stop.
Florida v. Bostick, 501 U.S. 429 (1991), was a United States Supreme Court case that overturned a per se rule imposed by the Florida Supreme Court that held consensual searches of passengers on buses were always unreasonable. The Court ruled that the fact that the search takes place on a bus is one factor in determining whether a suspect feels free to decline the search and walk away from the officers.
South Dakota v. Opperman, 428 U.S. 364 (1976), elaborated on the community caretaking doctrine. Under the Fourth Amendment, "unreasonable" searches and seizures are forbidden. In addition to their law enforcement duties, the police must engage in what the Court has termed a community caretaking role, including such duties as removing obstructions from roadways in order to ensure the free flow of traffic. When the police act in this role, they may inventory cars they have seized without "unreasonably" searching those cars.
Ohio v. Robinette, 519 U.S. 33 (1996), was a United States Supreme Court case in which the Court held that the Fourth Amendment does not require police officers to inform a motorist at the end of a traffic stop that they are free to go before seeking permission to search the motorist's car.
Ker v. California, 374 U.S. 23 (1963), was a case before the United States Supreme Court, which incorporated the Fourth Amendment's protections against illegal search and seizure. The case was decided on June 10, 1963, by a vote of 5–4.
United States v. Ortiz, 422 U.S. 891 (1975), was a United States Supreme Court case in which the Court held that the Fourth Amendment prevented Border Patrol officers from conducting warrantless, suspicionless searches of private vehicles removed from the border or its functional equivalent.
Wilson v. Arkansas, 514 U.S. 927 (1995), is a United States Supreme Court decision in which the Court held that police officers must "knock and announce" before entering a house to serve a warrant.
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."
Missouri v. McNeely, 569 U.S. 141 (2013), was a case decided by United States Supreme Court, on appeal from the Supreme Court of Missouri, regarding exceptions to the Fourth Amendment to the United States Constitution under exigent circumstances. The United States Supreme Court ruled that police must generally obtain a warrant before subjecting a drunken-driving suspect to a blood test, and that the natural metabolism of blood alcohol does not establish a per se exigency that would justify a blood draw without consent.
United States v. Drayton, 536 U.S. 194 (2002), was a case in which the United States Supreme Court clarified the applicability of Fourth Amendment protections to searches and seizures that occur on buses, as well as the function of consent during searches by law enforcement. During a scheduled stop in Tallahassee, Florida, police officers boarded a Greyhound bus as part of a drug interdiction effort and interviewed passengers. After talking to two of the passengers and asking if they could "check [their] person", officers discovered the two passengers had taped several packages of cocaine to their legs. At trial, the passengers argued that officers violated their Fourth Amendment rights against unreasonable searches and seizures because the police engaged in coercive behavior and never informed them that their participation in the drug interdiction efforts was voluntary.
Birchfield v. North Dakota, 579 U.S. ___ (2016), was a case in which the Supreme Court of the United States held that the search incident to arrest doctrine permits law enforcement to conduct warrantless breath tests but not blood tests on suspected drunk drivers.
This article is a chronological list of United States criminal case law articles on Wikipedia that discuss the Fourth Amendment constitutional provision against unreasonable search and seizure in its relation to consent to search.
