Police have a right to temporarily stop individuals whose behavior seems suspicious, to detain them briefly for questioning, and to pat them down. Stop and frisk is justified on the grounds of crime control and public safety. In Terry v. Ohio (1968), the Supreme Court held that when a police officer observes “unusual conduct” that leads him or her to think that criminal activity “may be afoot,” the officer can search the outer clothing of the suspect to discover weapons. Such a search, the Court said, must be based on reasonable suspicion. If officers suspect that an individual may be committing, may be about to commit, or may have committed a crime, they can stop, question, and pat down the individual. Reasonable suspicion is a lower standard of evidence than probable cause. The Court reasoned that since a stop is a lesser deprivation of freedom than an arrest and stop and frisk is less intrusive than a full‐body search, stops require fewer facts than probable cause. A police officer does not have to directly observe the facts upon which reasonable suspicion is based. Hearsay and/or an anonymous tip can be the basis of suspicion.
Drug Enforcement Administration agents and other police closely watch airports, bus stations, and interstate highways for people who may be transporting illegal drugs. Sometimes drug enforcement agents base their stops of suspected drug traffickers on tips from informants. Many times, however, the agents stop people like Joe Morgan who fit a drug courier profile, a set of factors, that taken together, identify drug runners based on their personal characteristics, mannerisms, and modus operandi, or general method of operation. Acting on reasonable suspicion of drug possession, police can briefly stop and question individuals to find out if they are carrying drugs.
Critics contend that profiles discriminate against racial minorities. Some studies support this claim. For example, a 1997 study found that African‐American motorists stopped on the Florida Turnpike by an all‐white Orange County (Orlando) sheriff's drug enforcement squad were six and a half times more likely to be searched than white drivers. Forty percent of the black motorists were searched, while only 6 percent of the whites were searched. Researchers explained these disparities in terms of the belief on the part of the police that blacks are more likely than whites to be trafficking in cocaine on Florida highways.
Are such racially biased search procedures legal? Even though the Supreme Court upheld the constitutionality of drug courier profiles in U.S. v. Sokolow (1989), Justice Thurgood Marshall's dissent pointed out serious flaws in profiles. Marshall disagreed with the majority's ruling that the reasonable suspicion level of proof is met simply by the police identification of a suspect as having characteristics that fit a drug courier profile. Once the police establish this level of proof, the Court declared, a Terry stop is permissible. Marshall demonstrated the falsity of this premise in the majority's argument by pointing out that the Terry rule requires evidence of ongoing criminality—such as casing a store before robbing it—to establish reasonable suspicion. As Marshall noted, most profiles do not meet such a standard.
Marshall also challenged the validity of drug courier profiles. From journalistic reports, it appears that the “hit,” or success, rate of these profiles (in other words, correct predictions that a person is indeed transporting drugs) is no better than the results that could be obtained by flipping a coin (in other words, 50 percent). Even worse, some profiles include a race/ethnicity factor which makes them racially biased and violative of the equal protection clause of the Fourteenth Amendment.