Whether respondent's sudden and unprovoked flight from an identifiable policeofficer in a high-crime area gave rise to a reasonable suspicion that respondentwas involved in criminal activity, justifying a temporary investigativedetention.


In the Supreme Court of the United States

No. 98-1036
STATE OF ILLINOIS, PETITIONER

v.

SAM WARDLOW

ON WRIT OF CERTIORARI
TO THE SUPREME COURT OF ILLINOIS

BRIEF FOR THE UNITED STATES AS
AMICUS CURIAE SUPPORTING PETITIONER

This case presents the question whether and under what circumstances anindividual's flight from an identifiable police officer will give rise toa reasonable suspicion of criminal wrongdoing justifying a temporary investigativedetention. The Court's resolution of that question will affect the practicesof federal law enforcement agents who encounter that situation. The dispositionof this case will also affect the admission in federal prosecutions of evidenceobtained by federal, state, and local police officers who apprehend suspectsafter such flight.

1. On September 9, 1995, Police Officer Timothy Nolan, a nine-year veteranwith the Chicago Police Department, was investigating narcotics sales inthe 11th District. Officer Nolan and his partner Officer Harvey were amongeight officers in four police cars traveling in a "caravan" easton West Van Buren Street. Officers Nolan and Harvey were in the last carof the caravan. Officer Nolan was dressed in full police uniform, whichincluded his badge, name tag, and Chicago Police Department arm patch. Atthe hearing conducted on respondent's motion to suppress, Officer Nolantestified that the area in question had a high incidence of narcotics trafficking.Officer Nolan further testified that he did not remember if his police carwas marked or unmarked. Pet. App. 1-2, 13-14; J.A. 4, 7-10.
As the four cars traveled down West Van Buren, Officer Nolan noticed respondentSam Wardlow standing in front of 4035 West Van Buren, looking in their direction.When respondent saw the officers approaching, he began to run. He was carryinga white opaque bag under his arm. As Officers Nolan and Harvey followedin their car, respondent ran south down a gangway and through an alley,but the officers caught up with and cornered him. Officer Nolan conducteda protective "pat-down" search of respondent and the bag he wascarrying.1 When he squeezed the bag, Officer Nolan felt a hard object similarin shape to a revolver. Officer Nolan looked inside the bag and found a.38 caliber Colt handgun loaded with live rounds of ammunition. Respondentwas then arrested. Pet. App. 1-2, 15; J.A. 4-11.2

2. Following his indictment on various weapons charges, respondent fileda motion to suppress the seized gun. After conducting an evidentiary hearingat which Officer Nolan testified to the events leading to respondent's arrest,the trial court denied the motion. J.A. 13-15. The court observed that "[a]lmostanybody can identify a police car marked or * * * unmarked," J.A. 14,and it concluded that "once a person flees after having looked in thedirection of the officer there's reasonable-there's reason to think there'sa problem, they have a right to make inquiry," J.A. 15.
After a bench trial at which the parties stipulated to the testimony introducedat the suppression hearing, respondent was convicted of unlawful use ofa weapon by a felon and sentenced to two years' imprisonment. Pet. App.15; 12/6/95 Tr. 15-20.

3. The Appellate Court of Illinois reversed. Pet. App. 13-19. The courtfound Officer Nolan's testimony "simply too vague to support the inferencethat [respondent] was in a location with a high incidence of narcotics trafficking."Id. at 17. The court then held that respondent's "sudden flight froman area past which police officers were driving" was insufficient,standing alone, to "satisfy the requirements for a lawful investigatorystop." Id. at 18.

4. The Supreme Court of Illinois affirmed. Pet. App. 1-12. The court foundthat "Officer Nolan's uncontradicted and undisputed testimony, whichwas accepted by the trial court, was sufficient to establish that the incidentoccurred in a high-crime area." Id. at 5. It therefore framed the questionpresented by the appeal as "whether an individual's flight upon theapproach of a police vehicle patrolling a high-crime area is sufficientto justify an investigative stop of the person." Ibid. The court agreedwith respondent that "such flight alone is insufficient to create areasonable suspicion of involvement in criminal conduct." Ibid.
Relying substantially on the Nebraska Supreme Court's decision in Statev. Hicks, 488 N.W.2d 359 (1992), cert. denied, 507 U.S. 1000 (1993), thecourt concluded that a rule permitting investigative stops based on flightalone would "upset the balance struck in Terry [v. Ohio, 392 U.S. 1(1968),] between the individual's right to personal security and the public'sinterest in prevention of crime." Pet. App. 7 (quoting Hicks, 488 N.W.2dat 364). The court explained:
Flight upon approach of a police officer may simply reflect the exercise-attop speed-of the person's constitutional right to move on. Terry and [Floridav. Royer, 460 U.S. 491 (1983),] stand for the proposition that exerciseof this constitutional right may not itself provide the basis for more intrusivepolice activity.
* * * * *
A prime concern underlying the Terry decision is protecting the right oflaw-abiding citizens to eschew interactions with the police. Authorizingthe police to chase down and question all those who take flight upon theirapproach would undercut this important right.
Pet. App. 6-7 (quoting Hicks, 488 N.W.2d at 363-364) (citation and quotationmarks omitted). The court thus agreed with respondent's argument that "[i]fthe police cannot constitutionally force otherwise law-abiding citizensto move, the police cannot force those same citizens to stand still at theappearance of an officer." Id. at 8.
The Illinois Supreme Court further concluded that the high incidence ofnarcotics trafficking in the pertinent area did not give rise to a reasonablesuspicion that respondent was engaged in wrongdoing. The court noted thatthe officers "were not responding to any call or report of suspiciousactivity in the area." Pet. App. 10. It observed as well that respondent"gave no outward indication of involvement in illicit activity priorto the approach of Officer Nolan's vehicle," but "was simply standingin front of a building when the officers drove by." Ibid. The courtconcluded that "because Officer Nolan was not able to point to specificfacts corroborating the inference of guilt gleaned from [respondent's] flight,his stop and subsequent arrest of [respondent] were constitutionally infirm."Id. at 12. The court accordingly affirmed the judgment of the Illinois AppellateCourt reversing respondent's conviction. Ibid.

In Terry v. Ohio, 392 U.S. 1 (1968), and its progeny, this Court held thatthe Fourth Amendment permits brief investigative stops based on "reasonablesuspicion" of criminal wrongdoing. To protect the safety of the officersconducting such a stop, moreover, when law enforcement officers have a reasonablesuspicion that the individual may be armed and dangerous, they may conducta limited search for weapons. The reasonable suspicion standard does notrequire an officer to have probable cause to believe that an individualhas committed a crime. United States v. Sokolow, 490 U.S. 1, 7 (1989). Rather,it requires only "some minimal level of objective justification,"INS v. Delgado, 466 U.S. 210, 217 (1984), for believing that the individual"is, or is about to be, engaged in criminal activity," UnitedStates v. Cortez, 449 U.S. 411, 417 (1981).
Respondent's sudden and unprovoked flight from the caravan of police carsand a uniformed police officer gave rise to a reasonable suspicion of hispossible involvement in criminal activity. Law enforcement officers havehistorically treated flight as a suspicious circumstance warranting furtherinvestigation. This Court has repeatedly held that efforts to evade policescrutiny are directly relevant to reasonable suspicion and probable causedeterminations. The Court has also recognized that flight may properly betreated as probative (though not conclusive) evidence of guilt in a criminalprosecution.
Flight from an identifiable police officer may be susceptible of innocentexplanations. The purpose of a Terry stop, however, is not to apprehendpersons who are known to be guilty of criminal offenses; it is to clarifysituations in which unlawful activity is suspected but probable cause hasnot been established. Unprovoked flight from identifiable police officersis ordinarily a sufficiently valid indicator of illicit conduct to justifya brief investigative stop. Although such flight may be undertaken for innocentreasons, it is not behavior in which innocent persons commonly engage -andit is far more likely to signal a consciousness of wrongdoing and a fearof apprehension. An immediate investigatory seizure is especially appropriatein these circumstances because the effect of flight is often to foreclosethe possibility of further observation of the individual that might revealadditional signs of unlawful behavior.
To treat flight as a basis for an investigative stop does not unlawfullyimpair an individual's right to avoid contact with the police. If respondenthad paid no attention to the officers, or had continued on his prior courseof conduct or activity, his decision to do that despite the police presencewould not (by itself) have justified an investigative stop. Instead, respondentdramatically altered his conduct in response to the officers' arrival, inan evident attempt to avoid police scrutiny. That pattern of activity ismuch more aberrational, and much more uncharacteristic of innocent persons,than a simple insistence on freedom from official interference.

RESPONDENT'S UNPROVOKED FLIGHT FROM POLICE OFFICERS PATROLLING A HIGH-CRIMEAREA GAVE RISE TO A REASONABLE SUSPICION OF CRIMINAL ACTIVITY AND JUSTIFIEDA TEMPORARY INVESTIGATIVE STOP BY THE POLICE

A. The Fourth Amendment Permits Limited Investigative Stops And AttendantProtective Searches Based On Reasonable Suspicion Not Rising To The LevelOf Probable Cause

The Fourth Amendment provides that "[t]he right of the people to besecure in their persons, houses, papers, and effects, against unreasonablesearches and seizures, shall not be violated." U.S. Const. Amend. IV.Under well-established precedent, the formal arrest of an individual is"reasonable" only if it is based on probable cause to believethat the person has engaged in unlawful activity. See, e.g., United Statesv. Watson, 423 U.S. 411, 417, 421 (1976). The probable cause standard alsoapplies, as a general matter, in determining the reasonableness of "searches."See, e.g., National Treasury Employees Union v. Von Raab, 489 U.S. 656,665 (1989); Griffin v. Wisconsin, 483 U.S. 868, 873 (1987).
Since its decision in Terry v. Ohio, 392 U.S. 1 (1968), however, this Courthas recognized that not every restriction on personal privacy or libertysufficient to constitute a "search" or "seizure" requiresthe degree of individualized suspicion necessary to satisfy the probablecause standard. Rather, the Court's decisions establish that "the policecan stop and briefly detain a person for investigative purposes if the officerhas a reasonable suspicion supported by articulable facts that criminalactivity 'may be afoot,' even if the officer lacks probable cause."United States v. Sokolow, 490 U.S. 1, 7 (1989). As the Court has explained:
The Fourth Amendment does not require a policeman who lacks the preciselevel of information necessary for probable cause to arrest to simply shrughis shoulders and allow a crime to occur or a criminal to escape. On thecontrary, Terry recognizes that it may be the essence of good police workto adopt an intermediate response. A brief stop of a suspicious individual,in order to determine his identity or to maintain the status quo momentarilywhile obtaining more information, may be most reasonable in light of thefacts known to the officer at the time.
Adams v. Williams, 407 U.S. 143, 145-146 (1972) (citation omitted).
The Court in Terry also recognized that an officer should not be requiredto take unreasonable risks when, in an investigatory stop, the suspect maybe "armed with a weapon that could unexpectedly and fatally be usedagainst him." Terry, 392 U.S. at 23. Rather, "[s]o long as theofficer is entitled to make a forcible stop, and has reason to believe thatthe suspect is armed and dangerous, he may conduct a weapons search limitedin scope to this protective purpose." Adams, 407 U.S. at 146 (footnoteomitted); see also, e.g., Minnesota v. Dickerson, 508 U.S. 366, 373 (1993)(an officer in conducting a Terry stop may search "on the basis ofreasonable suspicion less than probable cause," so long as the searchis "limited to that which is necessary for the discovery of weaponswhich might be used to harm the officer or others nearby").
The standard applicable to investigative stops and pat-down searches underTerry-a standard most often characterized as "reasonable suspicion"-"effectsa needed balance between private and public interests." United Statesv. Montoya de Hernandez, 473 U.S. 531, 541 (1985). Although the reasonablesuspicion standard precludes random or arbitrary seizures, or those basedmerely on a subjective "hunch," the burden of justification thatit imposes "is considerably less than proof of wrongdoing by a preponderanceof the evidence." Sokolow, 490 U.S. at 7. Rather, that standard requiresonly "some minimal level of objective justification to validate thedetention or seizure." INS v. Delgado, 466 U.S. 210, 217 (1984); seealso, e.g., United States v. Cortez, 449 U.S. 411, 417 (1981) ("Aninvestigatory stop must be justified by some objective manifestation thatthe person stopped is, or is about to be, engaged in criminal activity.").3

B. Flight Has Historically Been Treated As Probative Evidence Of InvolvementIn Criminal Activity

Under the foregoing principles, respondent's unprovoked flight from thecaravan of police cars and a uniformed police officer furnished a sufficientobjective basis for the officers to form a reasonable suspicion that hewas involved in criminal activity. Law enforcement officers have historicallytreated flight as a suspicious circumstance warranting further investigation.As one empirical study of police investigative practices concluded, "[c]ertainly,officers on patrol assume that flight is strong evidence of guilt. Theyalmost always attempt to stop and question a person who flees from them,even though they suspect no specific crime." Lawrence P. Tiffany etal., Detection of Crime 32 n.19 (Frank J. Remington ed. 1967). Because flight"may seem to indicate both the existence of a crime and participationin it by the person who flees," id. at 19, "[a] person who * ** changes his direction in an apparent attempt to avoid confronting [a police]officer, or who flees at the sight of an officer will commonly be detainedand questioned," id. at 32.4
That historical practice is eminently reasonable. This Court has repeatedlyheld that efforts to avoid police scrutiny are directly relevant to reasonablesuspicion and probable cause determinations. See, e.g., Sokolow, 490 U.S.at 8-9 (suspect's "evasive or erratic path through an airport,"and his apparent use of an alias, were factors relevant to the reasonablesuspicion inquiry); Florida v. Rodriguez, 469 U.S. 1, 6 (1984) ("Respondent'sstrange movements in his attempt to evade the officers aroused further justifiablesuspicion."); United States v. Brignoni-Ponce, 422 U.S. 873, 885 (1975)("erratic driving or obvious attempts to evade officers can supporta reasonable suspicion"); Sibron v. New York, 392 U.S. 40, 66-67 (1968)("deliberately furtive actions and flight at the approach of strangersor law officers are strong indicia of mens rea, and when coupled with specificknowledge on the part of the officer relating the suspect to the evidenceof crime, they are proper factors to be considered in the decision to makean arrest"); Husty v. United States, 282 U.S. 694, 701 (1931) (findingof probable cause for search of automobile was based on, inter alia, "theprompt attempt of [the defendant's] two companions to escape when hailedby the officers").5
To treat flight as evidence of possible criminal conduct is consistent notonly with this Court's Fourth Amendment jurisprudence, but with well-establishedprinciples of substantive criminal law. More than a century ago, this Courtobserved that "the law is entirely well settled that the flight ofthe accused is competent evidence against him as having a tendency to establishhis guilt." Allen v. United States, 164 U.S. 492, 499 (1896). Althoughflight cannot properly be treated as "conclusive proof of guilt,"Hickory v. United States, 160 U.S. 408, 421 (1896), "the flight ofthe accused is a circumstance proper to be laid before the jury, as havinga tendency to prove his guilt," Alberty v. United States, 162 U.S.499, 510 (1896).6

C. Respondent's Sudden Flight From Identifiable Police Officers Gave ThoseOfficers Reasonable Suspicion That He Was Involved In Criminal Activity

Courts that have refused to treat flight as a sufficient basis for a Terrystop have offered two basic justifications for that holding. First, courtshave sometimes reasoned that flight by itself is ambiguous, since it mayhave been inspired by innocent motives. See, e.g., Watkins v. State, 420A.2d 270, 273-274 (Md. 1980). Second, courts have expressed the view thatan individual's right to avoid contact with police would be impaired ifflight were accepted as a sufficient basis for an investigative stop. See,e.g., Pet. App. 6-7; State v. Hicks, 488 N.W.2d 359, 363-365 (Neb. 1992),cert. denied, 507 U.S. 1000 (1993); State v. Talbot, 792 P.2d 489, 493-494(Utah Ct. App. 1990); People v. Shabaz, 378 N.W.2d 451, 460-461 (Mich. 1985).Neither of those rationales withstands scrutiny.

1. Sudden flight from an identifiable police officer may be susceptibleof innocent explanations. Investigative detentions are routinely based,however, on conduct that is neither inherently blameworthy nor definitelyindicative of criminal behavior. As the Court explained in Sokolow,
"Innocent behavior will frequently provide the basis for a showingof probable cause," and * * * "[i]n making a determination ofprobable cause the relevant inquiry is not whether particular conduct is'innocent' or 'guilty,' but the degree of suspicion that attaches to particulartypes of noncriminal acts." That principle applies equally well tothe reasonable suspicion inquiry.
490 U.S. at 10 (quoting Illinois v. Gates, 462 U.S. 213, 243-244 n.13 (1983)).
Indeed, the point of this Court's Terry stop jurisprudence is to enablepolice officers "to adopt an intermediate response" when theypossess a degree of individualized suspicion not rising to the level ofprobable cause. Adams, 407 U.S. at 145. Situations in which probable causeis lacking are by definition situations in which the suspect's behavioris susceptible of an innocent explanation.7 Thus, "[d]oubtless, manyinnocent explanations for [respondent's] conduct could be hypothesized,but suspicious activity by its very nature is ambiguous. Indeed, the principalfunction of the investigative stop is to quickly resolve the ambiguity andestablish whether the suspect's activity is legal or illegal." Statev. Jackson, 434 N.W.2d 386, 391 (Wis. 1989).8
The propriety of the investigative stop in this case therefore does notdepend on a showing that respondent's flight unequivocally evidenced hisinvolvement in criminal activity. Rather, the stop was appropriate so longas respondent's behavior provided the "minimal level of objective justification"necessary to satisfy the reasonable suspicion standard. Sokolow, 490 U.S.at 7 (quoting INS v. Delgado, 466 U.S. 210, 217 (1984)). Unprovoked flightfrom identifiable police officers is ordinarily a sufficiently probativeindication of illicit conduct to justify a brief investigative stop. Althoughsuch flight may be undertaken for innocent reasons, it is not behavior inwhich innocent persons commonly engage. Compare Reid v. Georgia, 448 U.S.438, 441 (1980) (circumstances that "describe a very large categoryof presumably innocent travelers" could not provide the basis for aninvestigative stop). As the Wisconsin Supreme Court has explained,
[f]light at the sight of police is undeniably suspicious behavior. Althoughmany innocent explanations could be hypothesized as the reason for the flight,a reasonable police officer who is charged with enforcing the law as wellas maintaining peace and order cannot ignore the inference that criminalactivity may well be afoot. Although it does not rise to a level of probablecause, flight at the sight of a police officer certainly gives rise to areasonable suspicion that all is not well.
State v. Anderson, 454 N.W.2d 763, 766 (1990); see also 4 Wayne R. LaFave,Search and Seizure § 9.4(f), at 181-182 (3d ed. 1996) (agreeing that"behavior which evinces in the mind of a reasonable police officeran intent to flee from the police is sufficiently suspicious in and of itselfto justify a temporary investigative stop by the police").
The Illinois Supreme Court appeared to agree that an individual's flightfrom the police is relevant to the reasonable suspicion inquiry. It concluded,however, that an investigative detention is permissible only "if thereare corroborating circumstances sufficient to create the reasonable suspicionnecessary for the stop." Pet. App. 8. As we explain above, unprovokedflight is sufficiently unusual, and sufficiently uncharacteristic of innocentpersons, to satisfy the reasonable suspicion standard. There is, however,an additional flaw in the court's suggestion that officers observing a individual'sflight should seek evidence "corroborating" the inference of possiblecriminal involvement. In many if not most cases, the effect of flight isto foreclose the possibility that close observation of the individual willreveal additional signs of unlawful behavior. An immediate seizure is particularlyappropriate in cases, like the present one, in which officers have no practicalalternative means of further investigating the suspicious individual. Cf.Adams, 407 U.S. at 146 ("A brief stop of a suspicious individual, inorder to determine his identity or to maintain the status quo momentarilywhile obtaining more information, may be most reasonable in light of thefacts known to the officer at the time.") (emphasis added).
This Court has emphasized that in determining whether an investigative stopwas supported by reasonable suspicion, "the totality of the circumstances-the whole picture-must be taken into account." Cortez, 449 U.S. at417. Cases may occasionally arise in which other contextual factors refutethe inference of criminal activity that would otherwise attend an individual'sflight from identifiable police officers.9 In this case, however, the onlyadditional circumstance bearing on the reasonable suspicion inquiry wasthe fact that the episode occurred in a high-crime area. An individual'spresence in a high-crime neighborhood is not in itself sufficient to justifyan investigative stop. See Brown v. Texas, 443 U.S. 47, 52 (1979). Nor ispresence in a high-crime area necessary to justify an officer's conclusionthat sudden and unprovoked flight from an identifiable police officer givesrise to reasonable suspicion. But presence in such an area may contributeto a finding of reasonable suspicion when combined with other relevant circumstances,such as the flight in this case.10

2. In Florida v. Royer, 460 U.S. 491 (1983), a plurality of this Court statedthat an individual who is approached by the police
need not answer any question put to him; indeed, he may decline to listento the questions at all and may go on his way. He may not be detained evenmomentarily without reasonable, objective grounds for doing so; and hisrefusal to listen or answer does not, without more, furnish those grounds.
Id. at 498 (opinion of White, J.) (citation omitted). Some courts-includingthe Illinois Supreme Court in this case-have concluded that a Terry stopbased on an individual's flight from the police impairs the individual'sright to "go on his way" and is therefore inconsistent with Royer.See Pet. App. 6-7 (quoting Hicks, 488 N.W.2d at 363-364); Talbot, 792 P.2dat 494; Shabaz, 378 N.W.2d at 458, 460-461. That reasoning is erroneous.
The general constitutional bar on suspicionless seizures of the person reflectsthe fact that an individual has a liberty interest in pursuing his chosencourse of conduct free from official interference. In the Terry stop context,that interest may be overridden if, but only if, government officials havean objective basis for suspecting that the individual may be involved incriminal or similar wrongful behavior. The bar on suspicionless seizureswould be effectively negated if the police could request that an individualstop voluntarily, and then treat his refusal to do so as the basis for acompulsory stop. Thus, the Court has "consistently held that a refusalto cooperate, without more, does not furnish the minimal level of objectivejustification needed for a detention or seizure." Florida v. Bostick,501 U.S. 429, 437 (1991). The Royer plurality's recognition of the individual'sright to "go on his way," 460 U.S. at 498, and its assertion thatthe exercise of that right cannot provide the basis for a stop, ibid., arebest understood to refer to situations in which a person simply refusesto cease or modify his behavior in response to police entreaties.
Respondent, by contrast, did not insist on hewing to his predetermined courseof conduct. To the contrary, respondent dramatically altered his behaviorin direct response to the officers' arrival, and in an evident attempt toavoid police scrutiny. That pattern of activity is much more aberrational,and much more uncharacteristic of innocent persons, than is a simple insistenceon freedom from official interference. To treat such behavior as groundsfor an investigative stop would not permit suspicionless seizures. Had respondentsimply ignored the officers, his refusal to alter his behavior in responseto their arrival would not have furnished a basis for an investigative stop.Recognition of that principle adequately protects the individual's rightto be free from arbitrary government intrusion. It is both unnecessary andcounterproductive to take the further step of barring police from drawingthe inferences that naturally flow from sudden and dramatic shifts in privateconduct.11
It is true that no state or federal law prohibited respondent from takingflight when Officer Nolan appeared. In that sense it is accurate to saythat respondent had a "right" to flee and could not be punishedfor that behavior. As we explain above, however (see pp. 14-15, supra),Terry stops are routinely undertaken on the basis of conduct that is notinherently unlawful.12 In Terry itself, the two suspects simply strolleddown a street and peered into a street window, met with and conversed witha third person, and continued on their way-but in a manner that gave riseto the suspicion that they were casing the store for a possible robbery.392 U.S. at 5-6. The fact that respondent could not be punished for theflight itself did not preclude the police from treating the flight as evidenceof possible involvement in criminal activity. Cf. Wisconsin v. Mitchell,508 U.S. 476, 489 (1993) ("The First Amendment * * * does not prohibitthe evidentiary use of speech to establish the elements of a crime or toprove motive or intent.").13