Top 10 Cases for Police Series, Part 8

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Editor's Note: With so many cases affecting policing, the question often arises regarding which are the most important. If a law enforcement professional could choose only 10 cases to examine, which would those be? Included in this series is a list of what experts Rolando del Carmen and Jeffery Walker consider to be the top 10 cases most influencing day-to-day policing in the U.S. Continuing from our last installment, in reverse order, we give you number 3: Terry v. Ohio, 392 U.S. 1 (1968).


A stop and frisk based on reasonable suspicion is valid.


A plainclothes officer with 39 years of experience, 35 years of which were as a detective and 30 years of which were in the same patrol area, observed two men standing on a street corner. It appeared that the two men were “casing” a store because each walked up and down the street, peering into the store window, and then both returned to the corner to confer. At one point the two men were joined by a third man, who talked to them and then left swiftly. After the officer observed the two rejoining the same third man a couple of blocks away, he approached them, identified himself, and asked for identification. Receiving a mumbled response, the officer patted down the outside clothing of the men. The officer retrieved weapons from Terry and one other man. Terry and the other man were charged with and convicted of carrying concealed weapons.


Is “stop and frisk” valid under the Fourth Amendment? YES.

Supreme Court Decision

The police have the authority to detain a person for questioning even without probable cause to believe that the person has committed or is committing a crime. Such an investigatory stop does not constitute an arrest and is permissible when prompted by both the observation of unusual conduct leading to a reasonable suspicion that criminal activity may be afoot and the ability to point to specific and articulable facts to justify the suspicion. Subsequently, an officer may frisk a person if the officer reasonably suspects that he or she is in danger.


“. . . [T]he police should be allowed to ‘stop’ a person and detain him briefly for questioning upon suspicion that he may be connected with criminal activity. Upon suspicion that the person may be armed, the police should have the power to ‘frisk’ him for weapons. If the ‘stop’ and the ‘frisk’ give rise to probable cause to believe that the suspect has committed a crime, then the police should be empowered to make a formal ‘arrest,’ and a full incident ‘search’ of the person. This scheme is justified in part by the notion that a ‘stop’ and a ‘frisk’ amount to a mere ‘minor inconvenience and petty indignity,’ which can properly be imposed upon the citizen in the interest of effective law enforcement on the basis of a police officer’s suspicion.” [Footnotes omitted.]

Case Significance

The Terry case made clear that the stop and frisk practice is valid. Prior to Terry, police departments regularly used stop and frisk either by law or by judicial authorization, but its validity was doubtful because the practice was based on reasonable suspicion rather than probable cause, which is necessary in arrest and search cases. The Court held that stop and frisk is constitutionally permissible despite the lack of probable cause for either full arrest or full search, and despite the fact that a brief detention not amounting to full arrest is a “seizure,” requiring some degree of protection under the Fourth Amendment.

For many more cases, see Briefs of Leading Cases in Law Enforcement, 8th ed., which includes short, easy-to-understand briefs of 185 cases of primary importance to law enforcement officials.


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