The U.S. Supreme Court sanctioned stop and frisk searches in Terry v. Ohio (1968). A police officer need only have a reasonable suspicion of criminal behavior to detain and question a person (the "stop"). For self-protection, the officer can at the same time carry out a limited pat-down search for weapons (the "frisk"). This rule applies whether the suspects are on foot or in a car. A "reasonable suspicion" requires more than a hunch or a mere distrust; the officer must have objective grounds, based on all of the circumstances, to suspect that a person is involved in criminal activity.
Example: Officer Crosby sees Stills and Nash talking normally on a street corner. Having a hunch that a drug transaction may be underway, the officer detains and frisks the pair. The officer finds a gun in Nash’s pocket and arrests him. Under these circumstances, Officer Crosby had no right to detain Stills and Nash in the first place. A "hunch" doesn’t authorize detention; an officer must have "articulable facts supporting a reasonable suspicion" (U.S. v. Hensley, U.S. Sup. Ct. 1985). Because the initial detention was improper, the frisk incident to that detention was also improper, and the result of the frisk—the gun—is inadmissible.
Example: Officer Jacks sees Jill hiding under the steps of an apartment building. As the officer approaches, Jill runs away. Officer Jacks chases and detains Jill and pats her down for weapons. The officer removes a hard object that turns out to be a plastic envelope containing burglar’s tools. Officer Jacks can legally seize the tools because Jacks had a reasonable basis for suspecting that Jill was engaged in criminal activity. The officer had the right to detain Jill, pat her down, and remove an object that might have been a weapon.
Example: Officer Ross spots Wade’s minivan on a little-used road sometimes frequented by drug smugglers. Wade is driving at a time when border patrol officers commonly change shifts. Officer Ross, who knows that drug smugglers often use minivans, runs a check on the vehicle and finds that it is registered to an address in a block notorious for drug smuggling. Officer Ross stops Wade and asks to search the van, and Wade consents. A subsequent search of the minivan reveals 130 pounds of marijuana. Under these circumstances, Officer Ross had a reasonable suspicion that Wade was engaged in illegal behavior. Because the stop was legal and the resulting search was consensual, the marijuana is admissible as evidence (U.S. v. Arvizu, U.S. Sup. Ct. 2002).
This article was excerpted from The Criminal Law Handbook, by Paul Bergman, J.D., and Sara J. Berman, J.D.