PEOPLE OF THE STATE OF MICHIGAN, PETITIONER V. MICHAEL MOSE CHESTERNUT No. 86-1824 In the Supreme Court of the United States October Term, 1987 On Writ of Certiorari to the Court of Appeals of Michigan Brief for the United States as Amicus Curiae Supporting Petitioner TABLE OF CONTENTS Interest of the United States Statement Summary of argument Argument: The Fourth Amendment does not require the suppression of the narcotics respondent discarded during his flight from the police A. The pursuit of an individual who flees at the sight of a police officer does not without more amount to a Terry stop 1. Police surveillance and the questioning of a pedestrian do not amount to a "search" or a "seizure" under the Fourth Amendment 2. Police pursuit of an individual in flight does not invariably amount to a stop and may be no more intrusive than surveillance or questioning 3. The pursuit of respondent did not constitute a stop B. A person's unprovoked flight from a police officer gives rise to a reasonable suspicion of criminal activity and justifies a temporary investigative stop by the police 1. The police may reasonably treat flight as significant evidence of guilt 2. The ambiguous nature of flight in some instances does not render unreasonable a police officer's reliance on flight as an indication that criminal activity may be afoot 3. Respondent's unprovoked flight justified an investigative detention for the purpose of questioning Conclusion QUESTIONS PRESENTED 1. Whether the simple pursuit of an individual who flees at the sight of a police officer amounts to a temporary investigative detention under Terry v. Ohio, 392 U.S. 1 (1968). 2. Whether flight from an identifiable police officer gives rise to a reasonable suspicion, justifying a temporary investigative detention. INTEREST OF THE UNITED STATES This case presents questions regarding the role of the Fourth Amendment when police pursue an individual who flees as the police approach. The questions raised by this case are important to law enforcement agencies generally, and their resolution is likely to have an impact on federal agencies responsible for enforcing narcotics and firearms laws. The resolution of those questions is also likely to affect the activities of law enforcement agencies in the District of Columbia and on federal reservations, where federal agencies have general enforcement responsibilities. Finally, the disposition of this case will have an indirect impact on federal prosecutions by affecting the admission in federal proceedings of evidence obtained as a result of the actions of local police. STATEMENT 1. At approximately 12:30 p.m. on December 19, 1984, four Detroit police officers, riding in a marked police cruiser, were conducting routine patrol duties in metropolitan Detroit. As the patrol car approached the intersection of Shoemaker and St. Clair Streets, one of the officers saw a car pull over to the curb. A man got out of the car and walked over to respondent, who was standing alone on the corner of the intersection. When the patrol car was about half a block from the corner, respondent spotted the car, turned, and immediately began to run away. Pet. App. 3a; J.A. 13-14, 19, 20-21. The officers followed respondent around the corner in their patrol car "to see where he was going" (J.A. 25). The cruiser quickly caught up with respondent and began "running parallel with him" (J.A. 21). At that point, repondent threw a number of packets to the ground. One of the officers, Kenneth Peltier, got out of the cruiser and picked up the packets, which contained a number of pills. Meanwhile, after discarding the packets respondent ran a few feet farther and stopped while Officer Peltier inspected the pills. Based on his experience as a paramedic, Officer Peltier concluded that the pills contained codeine. Respondent was then arrested for the possession of narcotics and was taken to the stationhouse. During an ensuing search incident to arrest, the police discovered another packet of pills in respondent's hatband, a packet containing heroin, and a hypodermic needle. J.A. 15-17, 22-26. 2. A preliminary hearing was held on April 3, 1985. Officer Peltier, who was the only witness, described the events of December 19. At the end of Officer Peltier's testimony, defense counsel moved to dismiss the charges on the ground that respondent had been unlawfully seized. The magistrate granted the motion and dismissed the complaint (J.A. 26-35). The magistrate concluded that the Fourth Amendment forbids police pursuit of an individual on the basis of flight alone, and he found that there were no other circumstances giving rise to a reasonable suspicion that respondent was involved in criminal activity (J.A. 33-34). The trail court upheld the magistrate's order (J.A. 2-10). 3. The Michigan Court of Appeals affirmed (Pet. App. 2a-8a). The court concluded that the "investigatory pursuit" of a fleeing individual amounts to a "stop" under Terry v. Ohio, 392 U.S. 1 (1968). The court also concluded that flight from the police does not by itself give rise to a reasonable suspicion necessary to justify a stop (Pet. App. 5a-6a). The court reasoned that "(c)ertainly, the fact that (respondent) ran may have aroused the officers(') general suspicion, but without some specific additional knowledge (respondent's flight) was insufficient to justify their pursuit and eventual stop" of respondent (id. at 7a). Finally, the court concluded that, because respondent's abandonment of the packets was "in direct response" to the officers' unlawful pursuit, the packets were properly suppressed (id. at 7a-8a). The Michigan Supreme Court thereafter denied petitioner leave to appeal (Pet. App. 9a-10a). SUMMARY OF ARGUMENT A. The Michigan courts labeled the police conduct in this case an "investigatory pursuit" and heal that such conduct constitutes a "seizure" within the meaning of the Fourth Amendment. That conclusion, however, ignores the wide variety of forms that police pursuit of an individual can take. Pursuit, whether on foot or in a patrol car, often constitutes nothing more than surveillance, which has never been thought of as a "seizure," even if the person being followed knows that he is being "tailed." And even if the police catch up with the person being followed and question him, their encounter may constitute nothing more than on-the-scene questioning of a kind that is not regarded as a Fourth Amendment seizure. Thus, it is not enough to characterize the police conduct as a "pursuit" and to hold that it therefore implicates the Fourth Amendment. Instead, the courts must examine the entire course of police conduct to determine whether the police, through physical force or a show of authority, have restrained an individual's liberty to the extent that a reasonable person would not feel free to leave. The "purusit" undertaken in this case was no more menacing than surveillance or on-the-scene questioning. The officers did not accost or physically restrain respondent before he fled or during his flight. Nor did the officers invoke their authority to bring respondent to a halt. They did not order him to stop; they did not obstruct his path with their patrol car; and they did not use the car's flashing lights or siren to signal for him to stop. None of the officers displayed a weapon or threatened to use one if respondent continued to flee. The officers simply followed respondent and drove along beside him as he ran. Those actions are not the kinds of intimidating or coercive measures that are necessary to constitute a Terry stop. B. Even assuming that the police conduct in this case constituted a Terry stop, it was lawful based on respondent's flight as the officers approached. Law enforcement officers regard flight as a suspicious circumstance warranting further investigation, because flight often indicates that a crime has been or is being committed, and that the person who is fleeing has some connection with it. The natural reaction that the police have to flight is also one that the criminal law has long deemed reasonable. While flight can be ambiguous and may not by itself supply probable cause for an arrest, probable cause is unnecessary for a Terry stop, which is justified if a police officer reasonably believes that criminal activity "may be afoot." The officers in this case reasonably concluded that respondent's unprovoked flight at the sight of their marked patrol car indicated that he may have possessed contraband or may have been involved in some other criminal activity. Respondent's flight therefore gave the officers sufficient grounds to conduct a Terry stop. ARGUMENT THE FOURTH AMENDMENT DOES NOT REQUIRE THE SUPPRESSION OF THE NARCOTICS RESPONDENT DISCARDED DURING HIS FLIGHT FROM THE POLICE Respondent was not arrested until after Officer Peltier examined the packets that respondent discarded during his flight from the patrol car and concluded that they contained codeine. At that point, the police had probable cause to arrest respondent for the illegal possession of narcotics. Accordingly, unless the officers' prior actions violated the Fourth Amendment, the narcotics discarded by respondent, as well as the evidence obtained during the ensuring search incident to his arrest, were admissible as evidence. The Michigan Court of Appeals' ruling that the officers' conduct violated the Fourth Amendment was based on two legal conclusions: first, that the pursuit of an individual who flees at the sight of a police officer is tantamount to a "stop" of that person under Terry v. Ohio, 392 U.S. 1 (1968), and therefore must be justified by a reasonable suspicion of criminal activity; and, second, that flight from a police officer does not by itself give rise to a reasonable suspicion of criminal activity. For the reasons that follow, we submit that both links in the court's reasoning are erroneous. /1/ A. The Pursuit Of An Individual Who Flees At The Sight Of A Police Officer Does Not Without More Amount To A Terry Stop The Michigan Court of Appeals ruled that the police conduct in this case constituted an "investigatory pursuit," which restricted respondent's freedom as soon as the pursuit began (Pet. App. 5a). The court therefore held that the pursuit was a "seizure" within the meaning of the Fourth Amendment and could be justified only if the police reasonably suspected that respondent was engaged in criminal activity. That conclusion ignores the wide variety of police conduct that is subsumed within the term "pursuit," much of which does not constitute a "seizure" at all. 1. Police surveillance and the questioning of a pedestrian do not amount to a "search" of a "seizure" under the Fourth Amendment The question whether police pursuit of someone in flight amounts to an unlawful "seizure" touches on two well-established law enforcement practices, surveillance and on-the-scene questioning, which the police often employ when they encounter suspicious conduct. Neither practice ordinarily implicates the Fourth Amendment. The reason is that the Fourth Amendment does not regulate police activity that is neither a "search" nor a "seizure," and surveillance and questioning ordinarily do not fit within either category. In United States v. Knotts, 460 U.S. 276 (1983), this Court made clear that police surveillance does not constitute a search under the Fourth Amendment. There, law enforcement authorities tracked a person suspected of being involved in narcotics through a combination of visual surveillance and monitoring an electronic tracking device previously installed in a container the person was transporting. The Court ruled that monitoring a suspect's whereabouts through the use of such electronic equipment was not a search, because the device revealed no information that could not equally have been gleaned through sustained visual observation of his journey. And the latter practice, the Court explained, has long been held not to constitute a search. 460 U.S. at 281-285. Accord United States v. Karo, 468 U.S. 705, 713-714 (1984). The Court has likewise established that on-the-scene questioning ordinarily does not implicate the Fourth Amendment. In Terry v. Ohio, supra, the Court held that a law enforcement officer may stop an individual and briefly detain him for questioning if the officer has a reasonable suspicion that the individual is connected with criminal actitivy. 392 U.S. at 21-22. But Terry also made clear that interactions between a police officer and an individual short of a formal "stop" are lawful even if the officer lacks a reasonable suspicion that criminal activity may be afoot. The Court found it "obvious()" that "not all personal intercourse between policemen and citizens involved 'seizures' of persons." Id. at 19 n.16. An encounter becomes a seizure only when "a police officer accosts an individual and restrains his freedom to walk away." Id. at 16. As the Court explained, "(o)nly when the officer, by means of physical force or show of authority, has in some way restrained the liberty of a citizen may (a court) conclude that a 'seizure' has occurred." Id. at 19 n.16. /2/ In several decisions since Terry, the Court has sought to clarify the distinction between a stop and an encounter falling short of a stop. In United States v. Mendenhall, 446 U.S. 544 (1980), two Members of the Court concluded that "a person has been 'seized' within the meaning of the Fourth Amendment only if, in view of all of the circumstances surrounding the incident, a reasonable person would have believed that he was not free to leave." 446 U.S. at 554 (opinion of Steward, J.) (footnote omitted). Applying that standard to the facts, Justices Stewart and Rehnquist found that Mendenhall had not been "seized," since the agents did no more than ask her for identification and for her airline ticket. Id. at 555. A majority of the Court later approved that standard in separate opinions in Florida v. Royer, 460 U.S. 491 (1983), and found that similar actions by the officers did not amount to a Terry stop. 460 U.S. at 497, 501 (plurality opinion); id. at 514 (Blackmun, J., dissenting); id. at 523 n.3 (Rehnquist, J., dissenting). See also Florida v. Rodriguez, 469 U.S. 1, 5-6 (1984). Finally, in INS v. Delgado, 466 U.S. 210 (1984), the Court expressly held that simple questioning by a law enforcement officer does not, without more, amount to a seizure. 466 U.S. at 216-217, 219-221. As the Court explained in Delgado, "(w)hile most citizens will respond to a police request, the fact that people do so, and do so without being told they are free not to respond, hardly eliminates the consensual nature of the response. Unless the circumstances of the encounter are so intimidating as to demonstrate that a reasonable person would have believed he was not free to leave if he had not responded, one cannot say that the questioning resulted in a detention under the Fourth Amendment." Id. at 216 (citation omitted). See generally 3 W. LaFave, Search and Seizure Section 9.2(h), at 405-414 (2d ed. 1987). Implicit in Terry, Mendenhall, Royer, and Delgado is the recognition that a seizure does not occur whenever a police officer identifies himself as such upon approaching an individual, even though doing so may be equivalent, in a broad sense, to a "show of authority," and notwithstanding that few people will feel they can walk away or ignore the officer. The average pedestrian will feel some sense of responsibility to cooperate with brief questioning or a request for identification by the police, out of a sense of civic duty, an obligation to defer to authority, or a belief that a refusal to cooperate will focus suspicion on him. Model Code of Pre-Arraignment Procedure Section 110.1 commentary at 259 (Proposed Official Draft 1975) (hereinafter Model Code). Regardless of its psychological or sociological wellsprings, however, voluntary cooperation with the police does not constitute the type of intrusion that implicates the protection of the Fourth Amendment. See INS v. Delgado, 466 U.S. at 216. As Professor LaFave has explained, the police, "without having later to justify their conduct by articulating a certain degree of suspicion, should be allowed 'to seek cooperation, even where this may involve inconvenience or embarrassment for the citizen, and even though many citizens will defer to this authority of the police because they believe -- in some vague way -- that they should'" cooperate with law enforcement authorities. 3 W. LaFave, supra, Section 9.2(h), at 411 (footnote omitted) (quoting Model Code Section 110.1 commentary at 258). For that reason, "if 'the moral and instinctive pressures to cooperate are in general sound and may be relied on by the police,' then a street encounter does not amount to a fourth amendment seizure merely because of those pressures -- that is, merely because the other party to the encounter is known to be a policeman." 3 W. LaFave, supra, Section 9.2(h), at 411-412 (footnote omitted) (quoting Model Code Section 110.1 commentary at 258.) That conclusion is consistent with what Terry saw as "the central inquiry under the Fourth Amendment -- the reasonableness in all the circumstances of the particular governmental invasion of a citizen's personal security." 392 U.S. at 19. Application of the standard enunciated in Terry requires balancing the interest in "'prevent(ing) arbitrary and oppressive interference by enforcement officials with the privacy and personal security of individuals'" and "the acknowledged need for police questioning as a tool in the effective enforcement of the criminal laws." United States v. Mendenhall, 446 U.S. at 553-554 (opinion of Steward, J.) (citation omitted); see Brown v. Texas, 443 U.S. 47, 50 (1979); Pennsylvania v. Mimms, 434 U.S. 106, 109 (1977). In the context of on-the-scene questioning, the privacy and liberty safeguarded by the Fourth Amendment are not threatened by allowing a police officer to rely on the natural willingness of most persons to cooperate with law enforcement authoritites. And the practice of conducting routine questioning without forcible detention is an extremely valuable weapon in the prevention and detection of crime. The intrusion occasioned by the approach and questioning of a pedestrian by the police is therefore one that society is willing to accept as reasonable even in the absence of any suspicion that the person approached is guilty of wrongdoing. 2. Police pursuit of an individual in flight does not invariably amount to a stop and may be no more intrusive than surveillance or questioning The Fourth Amendment analysis of surveillance and on-the-scene questioning makes it clear that it is wrong to treat all forms of police "pursuit" alike. The police will not always chase a person in flight with their "siren blaring" (Commonwealth v. Thibeau, 384 Mass. 762, 764, 429 N.E.2d 1009, 1010 (1981)), they will not necessarily "spr(i)ng from their car and over(take)" a suspect "under circumstances that make it seem that some form of detention is imminent" (States v. Saia, 302 So. 2d 869, 873 (La. 1974), cert. denied, 420 U.S. 1008 (1975)), and they will not invariably "pull alongside (an individual), * * * reach() out and grab()" and forcibly restrain him (Commonwealth v. Thibeau, 384 Mass. at 763, 429 N.E.2d at 1010), which are the types of circumstances that have persuaded some courts to treat police pursuit as a Terry stop from the outset of the chase. "Pursuit" may consist of nothing more than following someone as he runs away from a police cruiser, a circumstance that far more closely resembles traditional police surveillance than a Terry stop. But see In re D.J., No. 85-870 (D.C. Oct. 19, 1987), slip op. 2; People v. Thomas, 660 P.2d 1272, 1273-1274 (Colo. 1983). The actions that the police follow in pursuing a suspect are no less diverse than other types of encounters between the police and the public that occur daily. Some forms of police pursuit will culminate in a Terry stop once a person is overtaken, if the police forcibly detain him. Some will amount to a stop from the outset or from an early point in the chase, if the police command the person to halt and indicate that he is not free to go. But that will not be true in every case in which the police follow an individual. In some cases, conduct that can be termed "pursuit" does not constitute a seizure at all -- when, for example, the pursuit amounts to nothing more than surveillance. Even when the police catch up with the person being followed, their conduct, will often involve nothing more threatening than the typical approach of an officer to a pedestrian for the purpose of asking him questions. To consider such conduct a "seizure" is to deprive the term of any real meaning and to be unfaithful to this Court's decisions on surveillance and police questioning. The correct approach, accordingly, is to examine the entire course of police conduct from the moment the police begin to follow the individual until the encounter is brought to a close, either when the person is arrested or when he walks away. Whether and when a stop has occurred turns on when, if at all, the police exercise force or a show of authority to restrain the individual, or when the circumstances of the encounter become so intimidating that a reasonable person would believe that he is not free to leave. In determining whether an individual has been "seized," a court must disregard the individual's subjective sense of compulsion when he is being pursued by the police. Just as a pedestrian who is approached by the police may believe that he should answer their questions, so too a person who is followed by the police may conclude that he should not ignore the officers' presence. In both cases, the person may feel inhibited in going about his business, even though the police have not taken action that in any way objectively restricts his freedom. The individual's subjective assessment of his options should not determine whether the police have "seized" him by approaching him for questioning or following him as he flees. There should be no difference for this purpose between cases in which a person is stationary and cases in which he is moving when he is approached by the police. Some additional "intimidating" circumstance (INS v. Delgado, 466 U.S. at 216) beyond mere pursuit -- such as a show of authority or the use of force -- should be required to constitute a Terry stop. 3. The pursuit of respondent did not constitute a stop The officers violated no Fourth Amendment interest of respondent's simply by watching him as a man got out of a parked car and walked over to respondent on the corner. Nor did the officers act improperly by approaching the corner itself. Respondent was standing on a public street, and the officers were free to observe his actions or to approach him to ask him questions. After respondent left the corner, the officers would not have acted unlawfully by following respondent from a distance in order to keep track of his whereabouts. That sort of police conduct -- the very essence of surveillance -- raises no Fourth Amendment question. United States v. Knotts, supra. Only two factors distinguish this case from that one: Respondent believed that the officers saw him, and by fleeing once he saw the marked patrol car, respondent prevented the officers from taking any step short of a chase to learn what prompted his flight and where he was heading. The first factor is irrelevant. It cannot be the case that what is known in the vernacular as a "tail" becomes a "seizure" once the person under surveillance realizes that he is being followed. The second factor is also insufficient to constitute a stop. The limited steps that the officers took to "see where (respondent) was going" (J.A. 25) bore none of the earmarks of a traditional Terry stop. Respondent was not accosted by Officer Peltier or his partners. On the contrary, the officers were a half-block from the street corner where respondent was standing when he ran from their patrol car. The officers did not physically restrain respondent. Indeed, the reason the officers followed respondent was that he fled once he spotted their patrol car, and respondent stopped running of his own accord while Officer Peltier retrieved the discarded packets of codeine. The officers also did not invoke their authority as law enforcement agents to prevent or attempt to prevent respondent from leaving the street corner. They did not order him to halt; they did not obstruct his path with their patrol car; and they did not use the patrol car's overhead flashing lights or siren to signal for him to stop. Finally, none of the officers displayed a weapon or threatened to use one if respondent continued to flee. All the officers did was to follow respondent and drive along parallel to him as he ran. /3/ It is likely that respondent believed that it was not safe to remain on the corner because he was in possession of narcotics at the time. And he may well have anticipated, when the patrol car was driving parallel to him as he ran, that the officers were about to stop and apprehend him. It is probably also true that respondent believed that it was useless to try to escape once Officer Peltier retrieved the packets that respondent had discarded. But regardless of his subjective impressions, respondent was free throughout -- in the sense contemplated by Terry -- to act as he chose: to remain on the street corner, to walk away, or even to run. 392 U.S. at 19 n.16. As it happens, respondent first decided to flee and then decided to give up the ghost, all in response to the mere presence and simple pursuit of the police officers. Those two actions by the officers, we submit, fall well short of the type of intimidating or coercive action that is necessary to constitute a Terry stop. B. A Person's Unprovoked Flight From A Police Officer Gives Rise To A Reasonable Suspicion Of Criminal Activity And Justifies A Temporary Investigative Stop By The Police The Michigan Court of Appeals ruled that "flight from the police alone does not provide the reasonable suspicion necessary to justify" a Terry stop (Pet. App. 6a). That conclusion, too, is in error. Even if the officers are deemed to have seized respondent by their pursuit or by some other action during the course of respondent's flight, respondent's unprovoked flight from their marked patrol car gave rise to a reasonable suspicion that respondent was connected with criminal activity, justifying a temporary investigative detention for the purpose of questioning him. 1. The police may reasonably treat flight as significant evidence of guilt Law enforcement officers treat flight as a suspicious circumstance that warrants further investigation. As one empirical study of police investigative practices concluded, "(c)ertainly, officers on patrol assume that flight is strong evidence of guilt. They almost always attempt to stop and question a person who flees from them, even though they suspect no specific crime." L. Tiffany, D. McIntyre, Jr., & D. Rotenberg, Detection of Crime 32 n.19 (1967). Ordinarily, the police will rely on a combination of factors in deciding whether to stop and question an individual, because often no one factor will enable an officer to determine both whether a crime has been (or will be) committed and by whom. The police treat flight differently, however, because it may appear to indicate both the existence of a crime and participation in it by the person who is fleeing. Id. at 19. For that reason, "(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 detained and questioned." Id. at 32. The natural reaction that law enforcement officers have to the flight of an individual is eminently reasonable. The roots of the principle that flight is evidence of guilt may be as deep as the observation that "(t)he wicked flee when no man pursueth: but the righteous are bold as a lion." Proverbs 28:1. The criminal law has historically treated flight as evidence of guilt. More than 90 years ago, this Court endorsed the view that flight is probative of wrongdoing, concluding that "the law is entirely well settled that the flight of the accused is competent evidence against him as having a tendency to establish his guilt." Allen v. United States, 164 U.S. 492, 499 (1896). Although it is wrong to treat flight "under both divine and human law, (as) conclusive proof of guilt" (Hickory v. United States, 160 U.S. 408, 421 (1896)), "undoubtedly the flight of the accused is a circumstance proper to be laid before the jury, as having a tendency to prove his guilt" (Alberty v. United States, 162 U.S. 499, 510 (1896)). See generally 2 J. Wigmore, Evidence Section 276, at 122 (Chadbourn rev. 1979) (footnote omitted) ("It is universally conceded today that the fact of an accused's flight * * * (is) admissible as evidence of consciousness of guilt, and thus of guilt itself."); 1 C. Torcia, Wharton's Criminal Evidence Section 154, at 630-632 (14th ed. 1985). Accordingly, it is well settled that flight at the sight of a police officer, whether he is in plain clothes or in uniform, is significant evidence that a criminal undertaking is, was, or will soon be afoot. See, e.g., Husty v. United States, 282 U.S. 694, 701 (1931); Brinegar v. United States, 338 U.S. 160, 166 n.7 (1949); Peters v. New York, decided together with Sibron v. New York, 392 U.S. 40, 66-67 (1968); United States v. Brignoni-Ponce, 422 U.S. 873, 884-885 (1975); Florida v. Rodriguez, 469 U.S. at 6; United States v. Sharpe, 470 U.S. 675, 705 (1985) (Brennan, J., dissenting); United States v. Haye, 285 F.2d 32, 34 (4th Cir. 1987); United States v. Pope, 561 F.2d 663, 668-669 (6th Cir. 1977); United States ex rel. Richardson v. Rundle, 461 F.2d 860, 864 (3d Cir. 1972), cert. denied, 410 U.S. 911 (1973); 2 W. LaFave, supra, Section 3.6(e), at 62 & n.126; 3 id. Section 9.3(c), at 448-451 & nn.150, 154, & 156. This Court made that point expressly in Peters v. New York, supra. There, the Court considered the significance of flight from an off-duty police officer in civilian clothes. 392 U.S. at 48. The officer heard noises at the door of his apartment, and on investigation he saw two men he did not know tiptoeing furtively in the hall. They took flight when the officer appeared. The Court found that the officer's observations amounted to probable cause for an arrest, rather than simply a reasonable suspicion. Chief Justice Warren wrote for the Court (392 U.S. at 66-67 (footnote omitted)): It is difficult to conceive of stronger grounds for arrest, short of actual eyewitness observation of criminal activity. As the trial court explicitly recognized, deliberately furtive actions and flight at the approach of strangers or law officers are strong indicia of mens rea, and when coupled with specific knowledge on the part of the officer relating the suspect to the evidence of crime, they are proper factors to be considered in the decision to make an arrest. 2. The ambiguous nature of flight in some instances does not render unreasonable a police officer's reliance on flight as indication that criminal activity may be afoot The courts that have refused to treat flight as a justification for a Terry stop have reasoned that flight by itself is often ambiguous, since it may have been inspired by a number of entirely innocent motives, such as a dislike of authority, a fear of harassment or brutality at the hands of police, or a concern at the prospect of being mistakenly apprehended as the guilty party. E.g., In re D.J., slip op. 8-9 & n.4; see United States v. Green, 670 F.2d 1148, 1152 (D.C. Cir. 1981); Hinton v. United States, 424 F.2d 876, 879 (D.C. Cir. 1969) (flight alone does not amount to probable cause). These courts have required that flight be corroborated by some other additional suspicious circumstance in order to justify the inference that criminal activity may be afoot. E.g., In re D.J., slip op. 9-10; People v. Shabaz, 424 Mich. 42, 59, 378 N.W.2d 451, 459 (1985), cert. dismissed, No. 85-1265 (July 7, 1986); see United States v. Green, 670 F.2d at 1152. /4/ It is true that there are circumstances in which flight may be ambiguous. Those circumstances are illustrated by Wong Sun v. United States, 371 U.S. 471 (1963). In that case, a narcotics officer affirmatively misrepresented his purpose for being on the suspect's premises at 6 a.m. and did not dispel the misimpression created by his own ruse before the suspect fled. Moreover, the officer had no reason to believe that the suspect had committed a crime other than the tip of a previously untested informant, and it was not even clear that the man at the door was the person named by the informant. Under these circumstances, the Court found that the suspect's flight did not supply probable cause sufficient to justify breaking open the suspect's door and following him to the bedroom where his wife and child lay sleeping. Id. at 474. The Court concluded that the suspect's flight was "ambiguous" conduct that "signified a guilty knowledge no more clearly than it did a natural desire to repel an apparently unauthorized intrusion." Id. at 483 (footnote omitted). Wong Sun does not support the proposition that flight can never amount to a reasonable suspicion. Wong Sun involved not a stop but an arrest (and a particularly intrusive one). The significance of the suspect's flight was therefore measured against the higher standard of probable cause, which is unnecessary for a Terry stop. In making a Terry stop, a police officer is not required to eliminate all innocent explanations for a suspect's behavior, or even to determine that his actions are more likely to be culpable than innocent. /5/ Rather, an officer may act when he "observes unusual conduct which leads him reasonably to conclude in light of his experience that criminal activity may be afoot" (Terry v. Ohio, 392 U.S. at 30 (emphasis added)). That standard demands only "some minimum level of objective justification to validate the detention or seizure" (INS v. Delgado, 466 U.S. at 217). See also United States v. Cortez, 449 U.S. 411, 418 (1981); Illinois v. Gates, 462 U.S. 213, 230-232 (1983); Texas v. Brown, 460 U.S. 730, 742 (1983) (plurality opinion). /6/ Moreover, the factors supporting a finding of reasonable suspicion must be viewed in light of the inferences and deductions that a trained and experienced officer would make, "inferences and deductions that might well elude an untrained person." United States v. Cortez, 449 U.S. at 418; United States v. Mendenhall, 446 U.S. at 563 (opinion of Powell, J.); Brown v. Texas, 443 U.S. at 52 n.2 (a trained, experienced officer "is able to perceive and articulate meaning in given conduct which would be wholly innocent to the untrained observer"). This Court's conclusion in Wong Sun that, on the facts of that case, the suspect's flight was ambiguous and did not provide probable cause hardly supports the proposition that flight is always ambiguous and can never amount to a reasonable suspicion. Even in Wong Sun, the question of the probative force of the suspect's flight was a close one: four Justices thought that the suspect's flight under the circumstances satisfied even the higher standard of probable cause. Wong Sun, 371 U.S. at 500-503 (Clark, J., dissenting). /7/ It may often be the case that there is an innocent explanation for an individual's flight. The magistrate suggested that allowing "flight" to justify a Terry stop would enable the police to stop "joggers" at will (J.A. 33). While it is implausible to believe that respondent sprinted away from the officers just to go for a jog, that possibility could be present in other cases. A principal function of police investigative work, however, is to resolve such ambiguities to determine whether observed behavior is suspicious. The possibility that there may be an innocent explanation for conduct that "may * * * arouse() the officers(') general suspicion" (Pet. App. 7a) should not disable the police from undertaking the limited investigative activity that Terry and its offspring have recognized as a necessary and legitimate means of preventing or detecting crime. 3. Respondent's unprovoked flight justified an investigative detention for the purpose of questioning If respondent had remained standing on the corner of Shoemaker and St. Clair Streets, or if he had simply walked away, he likely would not have aroused suspicion where it did not otherwise exist. But respondent did more than stand still or just walk away; he turned and ran away from the officers' patrol car. Nothing in this Court's decisions remotely suggests that a person's constitutional right to go on his way prohibits the police from drawing inferences from the manner in which he exercises that right. If flight ordinarily has some probative value, as this Court has held, it is not difficult to conclude that the stop of respondent in this case was supported by a reasonable suspicion that he was connected with criminal activity. As noted above, a reasonable explanation for respondent's flight from the officers was that he believed it was no longer "safe" to stand on the corner because the officers were approaching, and he may have felt uncomfortable remaining on the corner if he possessed some type of contraband or a weapon. Unprovoked flight from an identifiable police officer is not only a suspicious circumstance, but it is one that is not likely to "describe a very large category of presumably innocent travelers" (Reid v. Georgia, 448 U.S. 438, 441 (1980)). To be sure, it was possible that in spite of respondent's suspicious behavior, no crime had been committed. But the fundamental lesson of Terry is that a stop is justified when crime "may be afoot"; the officers need not have probable cause to believe that an offense has been committed. Consider the alternative. Must the police, while routinely patrolling a neighborhood, sit by impassively when someone spies a patrol car, turns, and runs away for no apparent reason? To paraphrase Terry, it would be poor police work indeed for four police officers simply to shrug their shoulders and fail to investigate that conduct further. 392 U.S. at 23; see also Adams v. Williams, 407 U.S. 143, 145-146 (1972). /8/ "There is no war between the Constitution and common sense" (Mapp v. Ohio, 367 U.S. 643, 657 (1961)), and the Constitution should therefore demand no such illogical and unfortunate result. CONCLUSION The judgment of the Court of Appeals of Michigan should be reversed. Respectfully submitted. CHARLES FRIED Solicitor General WILLIAM F. WELD Assistant Attorney General WILLIAM C. BRYSON Deputy Solicitor General PAUL J. LARKIN, JR. Assistant to the Solicitor General NOVEMBER 1987 /1/ We also disagree with the court's holding that discarding property during a police pursuit is involuntary as a matter of law and cannot amount to abandonment (Pet. App. 7a-8a). See, e.g., Smith v. State, 333 So. 2d 91 (Fla. Dist. Ct. App. 1976); People v. Boodle, 47 N.Y.2d 398, 391 N.E.2d 1329, 418 N.Y.S.2d 352, cert. denied, 444 U.S. 969 (1979). Even when it is later determined that the police pursuit was unjustified because it was not based on a sufficient level of reasonable suspicion, the suspect's decision to discard property, such as narcotics or weapons, during the pursuit may be an act of sufficiently independent free will that the items should not be subject to suppression if they are subsequently recovered by the police. The State did not separately present that question in its petition, however, and we have therefore not addressed it here. /2/ Terry itself provided only limited guidance for determining when "personal intercourse between policemen and citizens" has become a "stop." The Court found that Terry had been seized when he was taken hold of, spun around, and patted down by a police officer (392 U.S. at 19), but the Court did not decide whether Terry had been restrained prior to that time, even though he had been approached by the officer and asked to supply some identification (id. at 19 n.16). Nonetheless, two members of the Court explained in concurring opinions that police questioning is not tantamount to a seizure if an individual is free "to ignore his interrogator and walk away." Id. at 33 (Harlan, J., concurring); id. at 34 (White, J., concurring). In Sibron v. New York, 392 U.S. 40 (1968), a companion case to Terry, the Court again was unable to discern from the record whether Sibron had been seized when a police officer approached him in a restaurant and told him to come outside. The Court indicated, however, that the proper test was whether Sibron had accompanied the officer "voluntarily in a spirit of apparent cooperation," rather than in submission to a "show of force or authority which left him no choice" Id. at 63. /3/ Conduct having more elements of coercion than the conduct in this case has been held not to constitute a stop. See, e.g., INS v. Delgado, 466 U.S. at 219-221 (agent tapped individual on the shoulder to get his attention and then questioned individual); Martinez v. Nygaard, No. 85-4327 (9th Cir. Nov. 2, 1987), slip op. 10 (same); United States v. $73,277, United States Currency, 710 F.2d 283, 288-289 (7th Cir. 1983) (agent walked alongside individual, identified himself as a federal officer, and asked if he could speak with the individual); United States v. Burrell, 286 A.2d 845, 846 (D.C. 1972) (officer placed his hand on person's elbow and said, "Hold it, sir, could I speak with you for a second?"); People v. King, 72 Cla. App.3d 346, 349, 139 Cal. Rptr, 926, 926 (1977) (officer called out to person walking away from a group, "Danny, stop, I want to talk to you"); People v. Long, 99 Ill.2d 219, 457 N.E.2d 1252 (1983) (officer followed an individual's truck in his patrol car without activating his siren or flashing lights and the person in the truck pulled over to the side of the road); State v. McGee, 381 N.W.2d 630, 631 (Iowa 1986) (officers pulled their car behind an individual's parked car as he was about to enter it, and the officers shouted the individual's name); State v. Sheffield, 62 N.J. 441, 303 A.2d 68, cert. denied, 414 U.S. 876 (1973) (officer called over to defendant from a patrol car; when defendant walked quickly away, the officer followed him and again called his name.) /4/ In some cases, courts have ruled that the police may not rely on a person's flight to justify a Terry stop if his flight was a response to prior unlawful police conduct. Johnson v. United States, 468 A.2d 1325, 1328 (D.C. 1983); Commonwealth v. Thibeau, 384 Mass. at 764, 429 N.E.2d at 1010. No such claim could be made in this case, since respondent fled immediately upon the approach of the patrol car, before the police took any action at all. /5/ Indeed, even the probable cause standard for an arrest does not require that it be more likely than not that a person has committed a crime; only a "fair probability" of criminality is necessary. Illinois v. Gates, 462 U.S. 213, 235, 238, 243-244 n.13 (1983). In fact, the reasonable doubt standard applicable at trial does not require a court to find that the evidence is inconsistent with some conceivable hypothesis of innocence. Holland v. United States, 348 U.S. 121, 139-140 (1954). /6/ See 3 W. LaFave, supra, Section 9.3(b). at 431 ("it would seem clear (from Terry) that a more-probable-than-not standard is never applicable to a brief stopping for investigation"); id. at 432 & n.58 (collecting cases in which courts "quite properly" upheld a Terry stop even though the actions observed were consistent with innocent activity). /7/ This Court's decision in Ablerty v. United States, supra, is sometimes cited as authority for the proposition that flight alone cannot give rise to probable cause or a reasonable suspicion of criminal activity. See Hinton v. United States, 424 F.2d at 879 n.8; In re D.J., slip op. 8-9 & n.4. But the holding in Alberty has no bearing on this issue. In that case, as in Hickory v. United States, 160 U.S. at 422-423, and Starr v. United States, 164 U.S. 627 (1897), the Court ruled that the jury may not be instructed at trial on a defendant's flight in terms that treat flight as a conclusive presumption of guilt, because the defendant's flight may have an entirely innocent explanation. Alberty, 162 U.S. at 511. The principle that flight does not invariably indicate guilt, however, is not inconsistent with a police officer's judgment that flight is suspicious in a particular case, because flight is not required conclusively to establish guilt before an officer is entitled to make a Terry stop. /8/ As Illinois Supreme Court Justice Walter Schaefer put it (3 W. LaFave, supra, Section 9.3(b), at 433 n.60, quoting W. Schaefer, The Suspect and Society 41-42 (1967)): "'When writing opinions I have often been tempted to state the test of the reasonableness of a police officer's conduct in terms of what the reaction would have been if he had not done what he is charged with having done wrongfully. "If you would fire the officer for not doing what he did, then what he did was reasonable." * * * I agree that it isn't a very stylish way of expressing the concept of reasonableness, and that somewhat circular reasoning is involved. But to me there is value in restating the question so that the whole problem may be seen.'"