reasonable suspicion
Reasonable suspicion is a standard used in criminal procedure to evaluate whether a police officer’s decision to briefly stop an individual, or to conduct a limited search, complies with the Fourth Amendment of the U.S. Constitution. Reasonable suspicion requires specific facts that would lead a reasonable officer to believe that criminal activity may be occurring. The standard demands more than an unparticularized hunch, but less than the level of certainty required for probable cause.
Courts recognize different levels of justification for police intrusions, which vary in scope and authority. A search warrant provides the strongest justification, followed by probable cause. Reasonable suspicion authorizes more limited actions and generally permits only brief investigative stops and limited searches designed to address immediate safety concerns.
In Terry v. Ohio, 392 U.S. 1 (1968) the Supreme Court held that a police officer may stop an individual and conduct a limited pat-down search for weapons if the officer reasonably believes that the person is armed and presently dangerous. The Court emphasized that the officer’s decision must be based on specific reasonable inferences drawn from the facts and circumstances. The purpose of such a search is not to discover evidence of a crime, but to ensure officer safety during the encounter.
The Supreme Court later addressed the scope of investigative stops in Hiibel v. Sixth Judicial District Court of Nevada, 542 U.S. 177 (2004) which upheld a Nevada statute requiring a person lawfully detained during a Terry stop to identify themselves by stating their name. The Court concluded that the statute did not impermissibly expand the scope of the stop and appropriately balanced individual privacy interests against legitimate governmental concerns.
[Last reviewed in February of 2026 by the Wex Definitions Team]
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