The name derives from Terry v. Ohio, 392 U.S. 1 (1968), in which the Supreme Court of the United States held that police may briefly detain a person who they reasonably suspect is involved in criminal activity; the Court also held that police may do a limited search of the suspect’s outer garments for weapons if they have a reasonable and articulable suspicion that the person detained may be “armed and dangerous”. When a search for weapons is authorized, the procedure is known as a “stop and frisk”.
To have reasonable suspicion that would justify a stop, police must be able to point to “specific and articulable facts” that would indicate to a reasonable person that a crime has been, is being, or is about to be committed. Reasonable suspicion depends on the “totality of the circumstances”, and can result from a combination of facts, each of which is by itself innocuous.
The search of the suspect’s outer garments, also known as a patdown, must be limited to what is necessary to discover weapons; however, pursuant to the “plain feel” doctrine, police may seize contraband discovered in the course of a frisk, but only if the contraband’s identity is immediately apparent.
In some jurisdictions, persons detained under the doctrine of Terry must identify themselves to police upon request. In Hiibel v. Sixth Judicial District Court of Nevada, 542 U.S. 177, the Court held that a Nevada statute requiring such identification did not violate the Fourth Amendment’s prohibition against unreasonable searches and seizures, or, in the circumstances of that case, the Fifth Amendment’s privilege against self incrimination.
Traffic stops 
A traffic stop is, for practical purposes, a Terry stop; for the duration of a stop, driver and passengers are “seized” within the meaning of the Fourth Amendment. Under federal law, drivers and passengers may be ordered out of the vehicle without additional justification by the officer, although such practices might not be authorized under state law depending on the jurisdiction. Drivers and passengers may be searched for weapons upon reasonable suspicion they are armed and dangerous. If police reasonably suspect the driver or any of the occupants may be dangerous and that the vehicle may contain a weapon to which an occupant may gain access, police may perform a protective search of the passenger compartment.
Without a warrant, probable cause, or the driver’s consent, police may not search the vehicle, but under the “plain view” doctrine may seize and use as evidence weapons or contraband that are visible from outside the vehicle.
See also 
- In keeping with common practice of the U.S. Supreme Court, the terms police and police officer are used throughout this article; however, a more appropriate term is peace officer (or sometimes law enforcement officer). In general, peace officers are civil employees charged with preserving the public peace and granted the authority to do so. Peace officers normally include police, sheriffs and their deputies, marshals, and often many other persons; those included vary among the states.
- For the Court in Berkemer v. McCarty 468 U.S. 420 (1984), Justice Marshall wrote
- “the usual traffic stop is more analogous to a so-called ‘Terry stop,’ see Terry v. Ohio, 392 U.S. 1 (1968)” (468 U.S. at 439)
- For the Court in Hiibel v. Sixth Judicial District, Justice Kennedy noted
- Beginning with Terry v. Ohio, 392 U. S. 1 (1968), the Court has recognized that a law enforcement officer’s reasonable suspicion that a person may be involved in criminal activity permits the officer to stop the person for a brief time and take additional steps to investigate further. (542 U.S. at 185)
- For the Court in Terry v. Ohio, Chief Justice Warren wrote
- Our evaluation of the proper balance that has to be struck in this type of case leads us to conclude that there must be a narrowly drawn authority to permit a reasonable search for weapons for the protection of the police officer, where he has reason to believe that he is dealing with an armed and dangerous individual, regardless of whether he has probable cause to arrest the individual for a crime. (392 U.S. at 27)
- In Terry v. Ohio, Chief Justice Warren wrote
- And in justifying the particular intrusion the police officer must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant that intrusion. (392 U.S. at 21)
- For the Court in United States v. Cortez, 449 U.S. 411 (1981), Chief Justice Burger wrote
- Courts have used a variety of terms to capture the elusive concept of what cause is sufficient to authorize police to stop a person. Terms like “articulable reasons” and “founded suspicion” are not self-defining; they fall short of providing clear guidance dispositive of the myriad factual situations that arise. But the essence of all that has been written is that the totality of the circumstances—the whole picture—must be taken into account. Based upon that whole picture the detaining officers must have a particularized and objective basis for suspecting the particular person stopped of criminal activity. (449 U.S. at 417–418)
- In Terry v. Ohio, Chief Justice Warren wrote
- He [Detective McFadden] had observed Terry, Chilton, and Katz go through a series of acts, each of them perhaps innocent in itself, but which taken together warranted further investigation.
- In Terry v. Ohio, Chief Justice Warren wrote
- Thus it must be limited to that which is necessary for the discovery of weapons which might be used to harm the officer or others nearby, and may realistically be characterized as something less than a ‘full’ search, even though it remains a serious intrusion. (392 U.S. at 26)
- The sole justification of the search in the present situation is the protection of the police officer and others nearby, and it must therefore be confined in scope to an intrusion reasonably designed to discover guns, knives, clubs, or other hidden instruments for the assault of the police officer. (392 U.S. at 29)
- For the Court in Minnesota v. Dickerson, 508 U.S. 366 (1993), Justice White wrote
- If a police officer lawfully pats down a suspect’s outer clothing and feels an object whose contour or mass makes its identity immediately apparent, there has been no invasion of the suspect’s privacy beyond that already authorized by the officer’s search for weapons; if the object is contraband, its warrantless seizure would be justified by the same practical considerations that inhere in the plain-view context. (508 U.S. at 375–376)
- Here, the officer’s continued exploration of respondent’s pocket after having concluded that it contained no weapon was unrelated to “[t]he sole justification of the search [under Terry:] . . . the protection of the police officer and others nearby.” 392 U.S., at 29. It therefore amounted to the sort of evidentiary search that Terry expressly refused to authorize, see id., at 26, and that we have condemned in subsequent cases. (508 U.S. at 378)
- For the Court in Berkemer v. McCarty, Justice Marshall wrote
- “most traffic stops resemble, in duration and atmosphere, the kind of brief detention authorized in Terry.” (468 U.S. 420, 439, n. 29)
- For a unanimous Court in Brendlin v. California, 551 U.S. 249 (2007), Justice Souter wrote,
- When a police officer makes a traffic stop, the driver of the car is seized within the meaning of the Fourth Amendment. The question in this case is whether the same is true of a passenger. We hold that a passenger is seized as well and so may challenge the constitutionality of the stop. (551 U.S. at 249)
- Brendlin was seized from the moment Simeroth’s car came to a halt on the side of the road (551 U.S. at 263)
- Pennsylvania v. Mimms, 434 U.S. 106 (1977) (per curiam) noted
- We hold only that once a motor vehicle has been lawfully detained for a traffic violation, the police officers may order the driver to get out of the vehicle without violating the Fourth Amendment’s proscription of unreasonable searches and seizures. (434 U.S. at 111, n. 6)
- For the Court in Maryland v. Wilson, 519 U.S. 408 (1997), Chief Justice Rehnquist wrote
- an officer making a traffic stop may order passengers to get out of the car pending completion of the stop. (519 U.S. at 413)
- Pennsylvania v. Mimms (per curiam) held
- Under the standard enunciated in that case [Terry]—“whether the facts available to the officer at the moment of the seizure or the search ‘warrant a man of reasonable caution in the belief’ that the action taken was appropriate”—there is little question the officer was justified. The bulge in the jacket permitted the officer to conclude that Mimms was armed and thus posed a serious and present danger to the safety of the officer. In these circumstances, any man of “reasonable caution” would likely have conducted the “pat down.” (434 U.S. at 112)
- For a unanimous Court in Knowles v. Iowa, 525 U.S. 113 (1998), Chief Justice Rehnquist wrote that police may
- perform a “patdown” of a driver and any passengers upon reasonable suspicion that they may be armed and dangerous (113 U.S. at 117–118, citing Terry)
- For the Court in Michigan v. Long, 463 U.S. 1032 (1983), Justice O'Connor wrote
- These principles compel our conclusion that the search of the passenger compartment of an automobile, limited to those areas in which a weapon may be placed or hidden, is permissible if the police officer possesses a reasonable belief based on “specific and articulable facts which, taken together with the rational inferences from those facts, reasonably warrant” the officer in believing that the suspect is dangerous and the suspect may gain immediate control of weapons. (463 U.S. at 1049)
- For a unanimous Court in Knowles v. Iowa, 525 U.S. 113 (1998)), Chief Justice Rehnquist wrote that police may
- conduct a “Terry patdown” of the passenger compartment of a vehicle upon reasonable suspicion that an occupant is dangerous and may gain immediate control of a weapon (525 U.S. at 118, citing Long)
- For the Court in Michigan v. Long, Justice O'Connor wrote
- If, while conducting a legitimate Terry search of the interior of the automobile, the officer should, as here, discover contraband other than weapons, he clearly cannot be required to ignore the contraband, and the Fourth Amendment does not require its suppression in such circumstances. (463 U.S. at 1050, citing Coolidge v. New Hampshire, 403 U.S. 443, 465 (1971))