§ 4.03. Ensuring the Legitimacy of Police Encounters

(a) Officers should exercise their authority to approach, stop, and arrest individuals, recognized in § 4.02, in a manner that promotes public safety and positive police–community relations, and minimizes harm.

(b) Officers should establish the legitimacy of their encounters with members of the public by treating individuals with dignity and respect, explaining (insofar as is not inconsistent with investigative objectives) the basis for the officers’ actions, giving individuals an opportunity to speak and be heard, and engaging in behaviors that convey neutrality, fairness, and trustworthy motives.

(c) Agencies should ensure that officers carry out these principles through policy, recordkeeping, and training and supervision of officers.


a. Generally. Officers have considerable discretion in deciding whether to initiate an encounter with a member of the public, issue a summons, or conduct an arrest. In some circumstances, the necessity of officer intervention is readily apparent. An officer may witness a crime in progress or observe an individual driving recklessly. Or an officer may see someone behaving in a manner that very likely is indicative of criminal activity. In Terry v. Ohio, 88 S. Ct. 1868 (1968), an officer observed a pattern of behavior that gave him strong reason to believe that the individuals involved had been casing a jewelry store. Intervening in those circumstances is good police work, and generally should be encouraged.

Much of the controversy surrounding the use of officer-initiated encounters falls on the other end of the spectrum. In some jurisdictions, officers are instructed to make large numbers of traffic and pedestrian stops in order to create opportunities to conduct searches or frisks to look for weapons or contraband. Officers make stops on the basis of less individualized, vague criteria, such as claiming that an individual has engaged in “furtive movements” while in a high-crime area. Officers also make stops to investigate low-level infractions, such as riding a bicycle on a sidewalk, trespassing, driving with a broken taillight, or failing to signal when changing lanes. The goal is to use the stop as a basis for investigating the possibility of more serious crimes—such as drug trafficking or possession of a firearm—for which the officer has little or no articulable suspicion. Similarly, officers walk up and down the aisles of buses and ask to search some passengers’ persons or luggage, again with little or no articulable suspicion.

There are a number of concerns with using officer-initiated encounters in this manner. All officer-initiated encounters impose some costs on the person stopped. At a minimum, the encounter takes up time, and can result in missed appointments and obligations. Individuals may experience the stops as frightening or intrusive. Any time an officer initiates an encounter with a member of the public, there also is some risk that the encounter could escalate and put both the officer and individual at risk of harm. Stops and arrests also can result in complaints against officers, as well as litigation against the department, particularly when they are conducted in the absence of individualized suspicion or are deployed in racially biased ways.

There are costs to public safety and the legitimacy of law-enforcement agencies as well. When officers stop or approach individuals on the basis of little or no suspicion, there is a much greater likelihood that the individual stopped will be innocent of any crime or violation. Individuals who are stopped may question the officers’ motives for stopping them, and may conclude that they were singled out unfairly. Numerous studies have found that individuals who are stopped and questioned by police—particularly if they are stopped frequently—are less likely to report crimes or otherwise cooperate with the police. In the aggregate, communities in which such stops are frequent may come to view these enforcement practices as evidence of institutionalized mistrust, which itself can undermine the legitimacy of the police and reduce residents’ willingness to cooperate with law enforcement, to the detriment of overall public safety.

Similar concerns are present when officers take steps to enforce minor offenses that are committed frequently by many citizens but largely ignored. Studies suggest that individuals routinely distinguish between legality and legitimacy. Individuals who are stopped or arrested may recognize that they are in fact guilty of violating a law, but nevertheless question the legitimacy of the officers’ actions—particularly if certain offenses are enforced more aggressively in some neighborhoods than in others.

Finally, there have been serious concerns expressed regarding the practice of conducting stops in order to check for outstanding warrants. In some jurisdictions, officers stop thousands of pedestrians and motorists each year for this reason. If a warrant is found—even for a minor offense, such as an unpaid traffic ticket—the officer can then make an arrest and conduct a more extensive search. Such stops often are justified based on suspicion of minor infractions, or may be lacking in justification entirely. Experience in jurisdictions across the United States makes clear that such pretextual use of traffic and pedestrian stops can significantly undermine perceptions of police legitimacy. And, as discussed above, they also can result in unnecessary intrusions on individual liberty, and may put both officers and members of the public at greater risk of injury. In developing policies and practices to limit the use of investigative encounters generally, agencies should consider adopting specific limitations either on the conduct of stops for the purposes of identifying outstanding warrants, or on the conduct of warrant checks themselves. As discussed in § 2.08, agencies also should consider revisiting existing warrant practices which, in some places, have resulted in there being more outstanding warrants than residents in the area.

Some have credited the use of these sorts of aggressive enforcement strategies with bringing down crime. Some studies suggest that making large numbers of stops in a particular area may have short-term effects on crime rates. But other studies suggest that situational approaches—like addressing littering or abandoned lots—contribute more to crime reduction in hotspots than proactive enforcement efforts do. Even if the evidence in favor of such efforts was stronger, using stops in this manner could raise safety and legitimacy concerns. Stops that fail to turn up evidence or contraband may not be a good use of officer time, yet still can increase the potential for violent conflict between officers and members of the public. Frequent use of stops and arrests for minor offenses may pull individuals into the criminal-justice system needlessly—at great cost both to the individuals and to others in the community. See also § 1.04. And to the extent that use of stops reduces residents’ willingness to cooperate and exacerbates police–community tensions, it may make it more difficult for the department to do its job.

b. When and how encounters should be conducted. To address these concerns, agencies should, at a minimum, limit the frequency with which encounters take place. When encounters do take place, agencies should adopt policies to ensure that officers treat individuals in a procedurally just way so as to minimize harm to individuals stopped, consistent with the principles outlined above.

First, agencies should limit the overall use of initial encounters, stops, and arrests to circumstances in which they directly promote public safety and minimize harm to the public. See also § 1.04. Arrests should not occur unless necessary to protect public safety or ensure appearance in court. And agencies should minimize the use of stops based on vague, non-individualized factors or broad demographic categories. For example, studies suggest that when officers focus on behavioral cues—such as conduct indicative of criminal activity—as opposed to nonbehavioral cues—such as an individual’s location or manner of dress—they are more likely to be correct in their suspicions regarding the target’s participation in criminal activity. Agencies also should avoid using stops as a pretext to investigate potential crimes that are unrelated to the basis for the stop. And agencies should, in partnership with their communities, decide under what circumstances enforcement of low-level offenses is consistent with the agencies’ public-safety goals. To the extent that particular offenses are deemed a priority, they should be enforced evenhandedly throughout a jurisdiction.

Second, agencies should ensure that once an officer decides to initiate an encounter or engage in an arrest, the officer uses the encounter as an opportunity to reinforce, rather than undermine, the legitimacy of the police. Officers can do this by engaging the principles of procedural justice––treating individuals respectfully, with dignity, and (when not inconsistent with investigative objectives) explaining their reasons for initiating an encounter or taking a particular enforcement action. Officers also should give individuals an opportunity to exercise “voice” during encounters, and generally should convey trustworthy motives. Officers should abide by these principles throughout the entire encounter, including as individuals are brought to the police station and decisions are made about the possession of their property.

c. Policies, recordkeeping, and supervision. Agencies should develop policies and enforcement priorities that are consistent with these Principles. Agencies should not impose minimum quotas for officer-initiated encounters, and should not evaluate officers based on the number of stops, citations, or arrests that they conduct. In particular, agencies must never impose quotas to generate revenue. As discussed in greater detail in § 13.03, agencies should instead evaluate officers’ conduct in ways that encourage them to work cooperatively with members of their communities and address their public-safety needs. Finally, agencies should work with other government officials and community members to develop alternative strategies for dealing with public-safety concerns. In addition, agencies should develop policies and practices to monitor and learn from the ways in which officers interact with members of the public. Many agencies have instituted data-collection programs to track stops, searches, and arrests. Doing so enables agencies to assess whether officers’ actions are effective and conducted in an unbiased manner. Requiring officers to record what actions they took—and importantly, why—also can encourage officers to reflect on their own decisions and to consider whether their actions are in fact consistent with department values and priorities. Other agencies have used body-worn-camera footage to assess whether officers are conducting themselves appropriately in the course of encounters. Video footage also can be useful for training purposes by giving officers clear examples of what is expected of them. Body cameras also can be used as an encounter occurs, or beforehand, for officers to articulate the reason for initiating an encounter. When body cameras are not available, contemporaneous stop reports are essential.

Reporters’ Notes

This Section draws the distinction between officers’ lawful authority to initiate encounters, which often involves considerable discretion, and the manner in which that discretion should be used. In particular, it addresses the use of encounters in circumstances in which the encounters are not immediately necessary to address ongoing or imminent public-safety risks. As prior notes underscore, some departments have adopted the tactic of using wide-scale, nonconsensual encounters in an effort to fight crime. Although there is some evidence that this “proactive” use of encounters can help reduce crime, there also is mounting evidence about the costs that use of these tactics can impose. See National Academies of Sciences, Engineering, and Medicine, Proactive Policing: Effects on Crime and Communities 177-206 (2018) (hereinafter National Academies Report).

Those who favor aggressive use of traffic and pedestrian stops justify their use in one of two ways. First, they argue that proactive stops enable officers to uncover illegal guns and drugs. Second, they point out that stopping large numbers of people can have a deterrent effect by sending a message that criminal conduct will not be tolerated, and that individuals should leave their contraband and weapons at home. See, e.g., Edwin Meese III & John G. Malcolm, Policing in America: Lessons from the Past, Opportunities for the Future (2017); Michael R. Bloomberg, ‘Stop and frisk’ keeps New York safe, Washington Post, Aug. 18, 2013. The first has not been borne out by the evidence. Study after study indicates that in situations in which proactive stops are utilized, hit rates tend to be quite low. See, e.g., Expert Report of Jeffrey Fagan at 63; Floyd v. City of New York, No. 08 Civ. 1034 (S.D.N.Y. 2008) (0.15 percent of stops in New York City resulted in seizure of a gun, and 1.75 percent in seizure of contraband); ACLU of Massachusetts, “Stop and Frisk Report Summary” (2014) (finding that just 2.5 percent of stops turned up weapons or contraband). As for the deterrent claim, the evidence is mixed. A small number of studies suggest that proactive use of stops and arrests in cities like New York has had a modest effect on crime. See, e.g., David Weisburd et al., Do Stop, Question, and Frisk Practices Deter Crime? 15 Criminology & Pub. Pol. 31 (2016). But that evidence is contested. See, e.g., Richard Rosenfeld & Robert Fornango, The Impact of Police Stops on Precinct Robbery and Burglary Rates in New York City, 2003-2010, 31 Justice Quarterly 96 (2014) (finding few effects). In addition, studies comparing the use of proactive stops and arrests to use of more holistic problem-solving tactics have found that the latter is more effective at bringing down crime. See Anthony A. Braga, The Effects of Hot Spots Policing on Crime, 31 Justice Quarterly 633 (2014).

In 2018, the National Academy of Sciences issued a comprehensive report that examined available evidence regarding the efficacy of various proactive enforcement strategies, including the use of traffic and pedestrian stops. National Academies Report. It found evidence to suggest that stop-and-frisk programs may help reduce crime when used in a targeted fashion in crime hotspots. Id. at 149. However, the Report cautioned that these outcomes “are generally observed only in the short term” (less than a year), and that there is little evidence about the extent to which these and other “proactive” approaches “will have crime prevention benefits at the larger jurisdictional level.” Id. at 5. The Report also stressed that “aggressive, misdemeanor arrest-based approaches to control disorder generate small to null impacts on crime.” Id. at 8.

Importantly, any purported gains to public safety must be weighed against the potential costs that use of these tactics can impose. Using stops in this manner can expose agencies and officers to lawsuits and complaints. The U.S. Constitution is clear that officers must have reasonable, articulable suspicion of criminal activity to justify a stop. When agencies encourage officers to make widespread use of stops based on vague, generalized criteria, there is a strong likelihood that a substantial number of stops will fall short of this constitutional threshold. See, e.g., U.S. Dept. of Justice, Investigation of the Newark Police Department 8 (2014) (hereinafter Newark DOJ Report) (finding that 93 percent of stops reported by Newark officers lacked reasonable suspicion). Major cities across the country—including New York, Boston, Philadelphia, Milwaukee, and Newark—have faced lawsuits over aggressive use of traffic and pedestrian stops based on insufficient cause and in a manner that disproportionately targets people of color. At the height of “stop and frisk” in New York, these encounters accounted for one-third of all complaints against officers.New York Civilian Review Board, January to June 2011 Report 6 (2011). In many cities, the proactive use of police stops resulted in litigation, which typically ended either with a judgment against the city or a consent decree. See, e.g., Floyd, supra; ACLU of Illinois, Stop and Frisk, https://www.aclu-il.org/en/campaigns/stop-and-frisk (last visited July 6, 2018) (describing settlement agreement); Bailey et al. v. City of Philadelphia et al., C.A. No. 10-5952, Settlement Agreement, available at https://www.aclupa.‌org/‌download_file/‌view_inline/744/198 (last visited July 6, 2018).

In addition, numerous studies and reports—as well as plentiful evidence in the public sphere—make clear that proactive use of stops can significantly impact police legitimacy and public trust. See, e.g., Tom R. Tyler, Jeffrey Fagan & Amanda Geller, Street Stops and Police Legitimacy: Teachable Moments in Young Urban Men’s Legal Socialization 11 J. Empirical Legal Stud. 751-785 (2014); Jennifer Fratello, Andrés F. Rengifo & Jennifer Trone, Vera Institute of Justice, Coming of Age with Stop and Frisk: Experiences, Self-Perceptions, and Public Safety Implications (2013); Charles Epp, et al., Pulled Over: How Traffic Stops Define Race and Citizenship 126-133 (2014). Widespread use of “stop and frisk” has led to countless protests in cities across the country. See, e.g., John Leland & Colin Moynihan, Thousands March Silently to Protest Stop-and-Frisk Policies, New York Times, June 17, 2012. Justice Department investigations in cities like Chicago and Newark have pointed to deep-seated frustration on the part of residents, primarily persons of color, who report being stopped repeatedly in their communities. Newark DOJ Report at 11; U.S. Dept. of Justice, Investigation of the Chicago Police Department 142 (2014). Indeed, criticism of such tactics stretches at least as far back as the 1960s, when two presidential commissions pointed to aggressive policing in minority communities as one of the root causes of hostility and mistrust. See The Kerner Report: The 1968 Report of the National Advisory Commission on Civil Disorders (1968); The Challenge of Crime in a Free Society: A Report by the President’s Commission on Law Enforcement and Administration of Justice (1967). Although agencies may have initiated proactive enforcement programs with all good intentions, the fact of the matter is that their overuse has alienated communities, lessened public trust in the police, and led to considerable social unrest.

Thus, this Section encourages agencies to adopt practices and policies to limit the use of police encounters to those that promote public safety without undermining public trust. Agencies can do this in a number of ways. A number of agencies have adopted enforcement strategies that deemphasize high-volume use of stops and arrest, and focus instead on problem solving and targeted deterrence. See, e.g., New York City Police Department, “Tackling Crime, Disorder, and Fear: A New Policing Model,” available at https://www1.nyc.gov/html/nypd/html/home/‌POA/‌pdf/Tackling_Crime.pdf. And they have reinforced through policy and training the fact that certain tactics, even if lawful, can potentially undermine community trust. See, e.g., Austin Police Department, Policy Manual § 306.5 (reminding officers that “overuse of the consent search can negatively impact the Department’s relationship with our community.”) Finally, states and individual agencies have adopted stop-data-collection programs to monitor officer use of encounters to ensure that officers act in a manner that is consistent with department values and priorities. See, e.g., Cal. Gov. Code § 12525.5 (requiring law-enforcement agencies to gather and report on traffic-stop and pedestrian-stop data); 625 Ill. Comp. Stat. Ann. 5/11-212 (same); Conn. Gen. Stat. § 54-1m (requiring collection of motor-vehicle-stop data).

Among the policies that agencies should specifically consider are policies to limit or prohibit the use of stops for the purpose of conducting a warrant check. There are—as countless studies have documented—an extraordinary number of outstanding warrants in the United States. See Strieff, 136 S. Ct. at 2073 (Kagan, J., dissenting) (citing studies). In Ferguson, Missouri, a town with just 21,000 residents, the U.S. Department of Justice found that there were 16,000 outstanding warrants. Dept. of Justice, Civil Rights Div., Investigation of the Ferguson Police Department 55 (2015) (hereinafter Ferguson Report). In Cincinnati, a study found that the city had 100,000 warrants with only 300,000 residents. See Helland & Tabarrok, The Fugitive: Evidence on Public Versus Private Law Enforcement from Bail Jumping, 47 J. Law & Econ. 93, 98 (2004) Some of these warrants may be years—or even decades—old. See, e.g., Preeti Chauhan et al., The Summons Report: Trends in Issuance and Disposition of Summonses in New York City, 2003–2014 (2015), https://www.jjay.cuny.edu/sites/default/files/news/‌Summons_Report_‌DRAFT_‌‌4_24_2015_v8‌.pdf (finding that more than 73,000 of the warrants stemming from summonses issued in 2003 were still open as of 2014).

The proliferation of warrants creates an incentive for officers to conduct stops in order to look for outstanding warrants—and then, if a warrant is found, to conduct a full-blown search to look for weapons or contraband. Indeed, some police manuals encourage officers to run warrant checks during all stops precisely because it could give rise to a reason to search. See Epp et al., Pulled Over at 33-36 (2014). In some jurisdictions, officers conduct thousands of stops and warrant checks each year. The use of stops in this manner raises all of the concerns about legitimacy and intrusiveness discussed above. It also potentially helps to perpetuate the system of fines and fees that falls disproportionately on the poor and on racial minorities. See, e.g., Ferguson Report at 42-61. For all of these reasons, agencies should consider policies to limit the use of stops for the purpose of conducting a warrant check. Jurisdictions also should, consistent with § 2.08, revisit existing warrant practices to minimize the various harms that the proliferation of warrants has caused.

Finally, the expanding literature on procedural justice—not to mention common sense—makes clear that the manner in which an officer conducts an encounter can shape how the encounter is perceived. See Tom R. Tyler & Yuen J. Huo, Trust in the Law: Encouraging Cooperation with the Police and the Law53 (2002); Tracey L. Meares & Peter Neyroud, Rightful Policing, Nat’l Inst. of Justice (2015); Stephen J. Schulhofer et al., American Policing at a Crossroads: Unsustainable Policies and the Procedural Justice Alternative, 101 J. Crim. L. & Criminology 335, 344-345 (2011). By treating people respectfully, explaining the basis for the stop and encounter, and giving people voice, officers can use the stops that necessarily will occur to promote the legitimacy of policing and enhance the agency’s mission. Section 1.06 talks about procedural justice in policing and accumulates the evidence in its support. A number of agencies have adopted this approach, training officers that every encounter is an opportunity to promote the community’s trust in the police and elicit its cooperation in promoting public safety. Wesley G. Skogan, Maarten Van Craen & Cari Hennessy, Training Police for Procedural Justice, 11 J. Exp. Criminology 319 (2014) (evaluating effectiveness of Chicago’s training program).

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