Introduction

Terry Stops and Frisks

Introduction

The Fourth Amendment protects the right of the people to be secure in their persons against unreasonable searches and seizures.¹ An arrest, the fullest kind of seizure, ordinarily requires probable cause, yet police work on the street rarely waits for probable cause to form. In Terry v. Ohio, a Cleveland detective named Martin McFadden watched two men walk the same stretch of sidewalk and pause at the same store window about a dozen times over ten to twelve minutes, conferring each time, while a third man joined them briefly and left.² McFadden concluded that the men were casing the store for a robbery and feared that they were armed. The case reached the Supreme Court on the premise that he lacked probable cause to arrest anyone.³ A rule with only two settings, walk away or arrest, would have forced him either to let a suspected robbery develop or to seize two men on grounds the Amendment does not accept.

Terry resolved that dilemma by recognizing a category between doing nothing and arresting. The Court held that police may briefly detain a person for investigation on less than probable cause when they have reasonable suspicion, supported by articulable facts, that the person is involved in criminal activity.⁴ Articulable facts are specific observations the officer can point to, which is why McFadden's repeated and coordinated sightings carried more weight than any general unease. The decision also created a second, separate permission: if the officer reasonably suspects that the person is armed and presently dangerous, the officer may pat down the outer clothing for weapons.⁵ Later decisions summarize the structure as two conditions. The stop itself must be lawful, and to move from the stop to a frisk the officer must separately and reasonably suspect that the person stopped is armed and dangerous.⁶ The conditions are separate because they answer different needs, since the stop serves the investigation while the frisk serves the safety of the officer and others. A stop for a nonviolent offense may therefore be fully lawful and still give the officer no ground to touch the person's clothing.

Three questions organize every street encounter in this chapter, and each later rule fits under one of them. The first is whether the police seized the person at all, since the Fourth Amendment's demand for justification applies only once a seizure occurs. The second is whether the stop was justified at its inception by reasonable suspicion drawn from specific facts, whether those facts come from the officer's own eyes or from a tip. The third is whether everything the officers did afterward stayed within its limits: whether a frisk had its own justification, whether the pat-down stayed within its proper scope, and whether the detention lasted no longer than its purpose required.⁷ The next section takes up Terry in full, beginning with McFadden's pat-down and the two-track structure the Court built around it.