Terry v. Ohio, 392 U.S. 1 (1968), was a landmark U.S. Supreme Court decision in which the court ruled that it is constitutional for American police to "stop and frisk" a person they reasonably suspect to be armed and involved in a crime. Specifically, the decision held that a police officer does not violate the Fourth Amendment to the U.S. Constitution's prohibition on unreasonable searches and seizures when questioning someone even though the officer lacks probable cause to arrest the person, so long as the police officer has a reasonable suspicion that the person has committed, is committing, or is about to commit a crime. The court also ruled that the police officer may perform a quick surface search of the person's outer clothing for weapons if they have reasonable suspicion that the person stopped is "armed and presently dangerous." This reasonable suspicion must be based on "specific and articulable facts," and not merely upon an officer's hunch.
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.
A traffic stop, commonly referred to as being pulled over, is a temporary detention of a driver of a vehicle and its occupants by police to investigate a possible crime or minor violation of law.
Reasonable suspicion is a legal standard of proof in United States law that is less than probable cause, the legal standard for arrests and warrants, but more than an "inchoate and unparticularized suspicion or 'hunch'"; it must be based on "specific and articulable facts", "taken together with rational inferences from those facts", and the suspicion must be associated with the specific individual. If police additionally have reasonable suspicion that a person so detained is armed and dangerous, they may "frisk" the person for weapons, but not for contraband like drugs. However, if the police develop probable cause during a weapons frisk, they may then conduct a full search. Reasonable suspicion is evaluated using the "reasonable person" or "reasonable officer" standard, in which said person in the same circumstances could reasonably suspect a person has been, is, or is about to be engaged in criminal activity; it depends upon the totality of circumstances, and can result from a combination of particular facts, even if each is individually innocuous.
United States v. Arvizu, 534 U.S. 266 (2002), is a case in which the Supreme Court of the United States unanimously reaffirmed the proposition that the Fourth Amendment required courts to analyze the reasonableness of a traffic stop based on the totality of the circumstances instead of examining the plausibility of each reason an officer gives for stopping a motorist individually.
Brendlin v. California, 551 U.S. 249 (2007), was a decision by the Supreme Court of the United States that held that all occupants of a car are "seized" for purposes of the Fourth Amendment during a traffic stop, not just the driver.
United States v. Brignoni-Ponce, 422 U.S. 873 (1975), was the case in which the Supreme Court determined it was a violation of the Fourth Amendment for a roving patrol car to stop a vehicle solely on the basis of the driver appearing to be of Mexican descent. A roving patrol car must have articulable facts that allow for an officer to have a reasonable suspicion that the person is carrying illegal aliens beyond their ethnicity. The Court handed down a 9–0 decision that affirmed the Circuit Court's ruling in the case.
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.
New York v. Belton, 453 U.S. 454 (1981), was a United States Supreme Court case in which the Court held that when a police officer has made a lawful custodial arrest of the occupant of an automobile, the officer may, as a contemporaneous incident of that arrest, search the passenger compartment of that automobile. Therefore, Belton extended the so-called "Chimel rule" of searches incident to a lawful arrest, established in Chimel v. California (1969), to vehicles. The Supreme Court sought to establish bright line rules to govern vehicle search incident to eliminate some confusion in the cases.
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."
Maryland v. Buie, 494 U.S. 325 (1990), was a decision by the Supreme Court of the United States handed down in 1990. In the case, the Court held that the Fourth Amendment permits a properly limited protective sweep in conjunction with an in-home arrest when the searching officer possesses a reasonable belief based on specific and articulable facts that the area to be swept harbors an individual posing a danger to those on the arrest scene.
Colorado v. Bannister, 449 U.S. 1 (1980), is a U.S. Supreme Court case concerning the automobile exception to constitutional protections against searches and seizures.
Schneckloth v. Bustamonte, 412 U.S. 218 (1973), was a U.S. Supreme Court case that ruled that in a case involving a consent search, although knowledge of a right to refuse consent is a factor in determining whether a grant of consent to a search was voluntary, the state does not need to prove that the person who granted consent to search knew of the right to refuse consent under the Fourth Amendment.
Kentucky v. King, 563 U.S. 452 (2011), was a decision by the US Supreme Court, which held that warrantless searches conducted in police-created exigent circumstances do not violate the Fourth Amendment as long as the police did not create the exigency by violating or threatening to violate the Fourth Amendment.
Pennsylvania v. Mimms, 434 U.S. 106 (1977), is a United States Supreme Court criminal law decision holding that a police officer ordering a person out of a car following a traffic stop and conducting a pat-down to check for weapons did not violate the Fourth Amendment to the United States Constitution.
Bailey v. United States, 568 U.S. 186 (2013), was a United States Supreme Court case concerning search and seizure. A 6–3 decision reversed the weapons conviction of a Long Island man who had been detained when police followed his vehicle after he left his apartment just before it was to be searched. Justice Anthony Kennedy wrote the majority opinion, and Antonin Scalia filed a concurrence. Stephen Breyer dissented.
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.
Ybarra v. Illinois was a decision of the U.S. Supreme Court which ruled that a warrant can not be used to search an unnamed individual unless the warrant mentions that unnamed parties are involved or exigent circumstances are shown to exist.
Rodriguez v. United States, 575 U.S. 348 (2015), was a United States Supreme Court case which analyzed whether police officers may extend the length of a traffic stop to conduct a search with a trained detection dog. In a 6–3 opinion, the Court held that officers may not extend the length of a traffic stop to conduct a dog sniff unrelated to the original purpose of the stop. However, the Court remanded the case to the United States Court of Appeals for the Eighth Circuit to determine whether the officer's extension of the traffic stop was independently justified by reasonable suspicion. Some analysts have suggested that the Court's decision to limit police authority was influenced by ongoing protests in Ferguson, Missouri.
Plumhoff v. Rickard, 572 U.S. 765 (2014), is a United States Supreme Court case involving the use of force by police officers during high-speed car chases. After first holding that it had jurisdiction to hear the case, the Court held that the conduct of the police officers involved in the case did not violate the Fourth Amendment to the U.S. Constitution, which prohibits unreasonable searches and seizures.
