Proactive policing, as a strategic approach used by police agencies to prevent crime, is a relatively new phenomenon in the United States. It developed from a crisis in confidence in policing that began to emerge in the 1960s because of social unrest, rising crime rates, and growing skepticism regarding the effectiveness of standard approaches to policing. In response, beginning in the 1980s and 1990s, innovative police practices and policies that took a more proactive approach began to develop. This report uses the term “proactive policing” to refer to all policing strategies that have as one of their goals the prevention or reduction of crime and disorder and that are not reactive in terms of focusing primarily on uncovering ongoing crime or on investigating or responding to crimes once they have occurred. Specifically, the elements of proactivity include an emphasis on prevention, mobilizing resources based on police initiative, and targeting the broader underlying forces at work that may be driving crime and disorder. This contrasts with the standard model of policing, which involves an emphasis on reacting to particular crime events after they have occurred, mobilizing resources based on requests coming from outside the police organization, and focusing on the particulars of a given criminal incident.
Proactive policing is distinguished from the everyday decisions of police officers to be proactive in specific situations and instead refers to a strategic decision by police agencies to use proactive police responses in a programmatic way to reduce crime. Today, proactive policing strategies are used widely in the United States. They are not isolated programs used by a select group of agencies but rather a set of ideas that have spread across the landscape of policing.
TABLE S-1 Four Approaches to Proactive Policing
|Place-Based Approach||Problem-Solving Approach||Person-Focused Approach||Community-Based Approach|
|Logic Model for Crime Prevention||Capitalize on the evidence for the concentration of crime at microgeographic places||Use a problem-oriented approach, which seeks to identify problems as patterns across crime events and then identify the causes of those problems
Draw upon solutions tailored to the problem causes, with attention to assessment
|Capitalize on the strong concentration of crime among a small proportion of the criminal population||Capitalize on the resources of communities to identify and control crime|
|Policing Strategies||Hot spots policing, predictive policing, CCTV||Problem-oriented policing, third party policing||Focused deterrence; repeat offender programs; stop, question, and frisk||Community-oriented policing, procedural justice policing, broken windows policing|
|Primary Objective||Prevent crime in microgeographic places||Solve recurring problems to prevent future crime||Prevent and deter specific crimes by targeting known offenders||Enhance collective efficacy and community collaboration with police|
|Key Ways to Accomplish Objective||Identification of crime hot spots and application of focused strategies||Scan and analyze crime problems, identify solutions and assess them (SARA model)||Identification of known high-rate offenders and application of strategies to these specific offenders||Develop approaches that engage the community or that change the way police interact with citizens|
The United States has once again been confronted by a crisis of confidence in policing. Instances of perceived or actual police misconduct have given rise to nationwide protests against unfair and abusive police practices. Although this report is not intended to respond directly to the crisis of confidence in policing that can be seen in the United States today, it is nevertheless important to consider how proactive policing strategies may bear upon this crisis. It is not enough to simply identify “what works” for reducing crime and disorder; it is also critical to consider issues such as how proactive policing affects the legality of policing, the evaluation of the police in communities, potential abuses of police authority, and the equitable application of police services in the everyday lives of citizens.
To that end, the National Institute of Justice and the Laura and John Arnold Foundation asked the National Academies of Sciences, Engineering, and Medicine to review the evidence and discuss the data and methodological gaps on (1) the effects of different forms of proactive policing on crime; (2) whether they are applied in a discriminatory manner; (3) whether they are being used in a legal fashion; and (4) community reaction. The Committee on Proactive Policing: Effects on Crime, Communities, and Civil Liberties was appointed by the National Academies to carry out this task.
The committee made a decision to prioritize proactive policing strategies that are commonly applied in U.S. police agencies; cutting-edge strategies that, though not yet widely adopted, represent important new methods for preventing crime; and strategies that raise concerns about biased or abusive outcomes. In the context of this report, proactive policing is regarded as a strategic concern and refers to the policy decisions of departments regarding the means and goals of policing and not to the individual actions of officers.
Proactive policing has taken a number of different forms over the past two decades, and these variants often overlap in practice. The four broad approaches for proactive policing described in this report are (1) place-based interventions, (2) problem-solving interventions, (3) person-focused interventions, and (4) community-based interventions. Table S-1 summarizes the four approaches and the strategies they encompass. The rest of this summary discusses the consequences of these approaches for law and legality, crime and disorder, community reactions, and racial bias and disparities.
LAW AND LEGALITY
However effective a policing practice may be in preventing crime, it is impermissible if it violates the law. The most important legal constraints on proactive policing are the Fourth Amendment to the U.S. Constitution, the Equal Protection Clause (of the Fourteenth Amendment), and related statutory provisions.
Although proactive policing strategies do not inherently violate the Fourth Amendment, any proactive strategy could lead to Fourth Amendment violations1 to the degree that it is implemented by having officers engage in stops, searches, and arrests that violate constitutional standards. This risk is especially relevant for stop, question, and frisk (SQF);2 broken windows policing;3 and hot spots policing interventions4 if they use an aggressive practice of searches and seizures to deter criminal activity.
In addition, in conjunction with existing Fourth Amendment doctrine, proactive policing strategies may limit the effective strength or scope of constitutional protection or reduce the availability of constitutional remedies. For example, when departments identify “high crime areas” pursuant to place-based proactive policing strategies, courts may allow stops by officers of individuals within those areas that are based on less individualized behavior than they would require without the “high crime” designation. In this way, geographically oriented proactive policing may lead otherwise identical citizen-police encounters to be treated differently under the law.
The Equal Protection Clause guarantees equal and impartial treatment of citizens by government actors. It governs all policies, decisions, and acts taken by police officers and departments, including those in furtherance of proactive policing strategies. As a result, Equal Protection claims may arise with respect to any proactive policing strategy to the degree that it discriminates against individuals based on their race, religion, or national origin, among other characteristics. Since most policing policies today do not expressly target racial or ethnic groups, most Equal Protection challenges require proving discriminatory purpose in addition to discriminatory effect in order to establish a constitutional violation.
Specific proactive policing strategies, such as SQF and “zero tolerance” versions of broken windows policing, have been linked to violations of both the Fourth Amendment and the Equal Protection Clause by courts in private litigation and by the U.S. Department of Justice in its investigations
1 The Fourth Amendment to the U.S. Constitution states: “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
2 When carried out as a proactive policing strategy, an SQF program relies upon the legal authority granted by court decisions to engage in frequent stops in which suspects are questioned about their activities, frisked if possible, and often searched, usually with consent.
3 In broken windows policing, the police seek to prevent crime by addressing disorder and less serious crime problems. Such police interventions are expected to reinforce and enhance informal social controls within communities.
4 Hot spots policing efforts focus on “micro” units of geography where crime is concentrated. Microgeographic areas are commonly defined to include a single street or a cluster of street segments.
of police departments. Ethnographic studies and theoretical arguments further support the idea that proactive strategies that use aggressive stops, searches, and arrests to deter criminal activity may decrease liberty and increase Fourth Amendment and Equal Protection violations. However, empirical evidence is insufficient—using the accepted standards of causality in social science—to support any conclusion about whether proactive policing strategies systematically promote or reduce constitutional violations [Conclusion 3-1]. In order to establish a causal link, studies would ideally determine the incidence of problematic behavior by police under a proactive policy and compare that to the incidence of the same behavior in otherwise similar circumstances in which a proactive policy is not in place.
However, even when proactive strategies do not lead to constitutional violations, they may raise concerns about deeper legal values such as privacy, equality, autonomy, accountability, and transparency [Conclusion 3-2]. Even procedural justice policing and community-oriented policing, neither of which are likely to violate legal constraints on policing (and, to the extent that procedural justice operates as intended, may make violations of law less likely), may, respectively, undermine the transparency about the status of police-citizen interactions and alter the structure of decision making and accountability in police organizations.
CRIME AND DISORDER
The available scientific evidence suggests that certain proactive policing strategies are successful in reducing crime and disorder. This important conclusion provides support for a growing interest among American police in innovating to develop effective crime prevention strategies. At the same time, there is substantial heterogeneity in the effectiveness of different proactive policing interventions in reducing crime and disorder. For some types of proactive policing, the evidence consistently points to effectiveness, but for others the evidence is inconclusive. Evidence in many cases is also restricted to localized crime prevention impacts, such as specific places, or to specific individuals. Relatively little evidence-based knowledge exists about whether and to what extent the approaches examined in this report will have crime prevention benefits at the larger jurisdictional level (e.g., a city as a whole or even large administrative areas such as precincts within a city), or across all offenders. Furthermore, the crime prevention outcomes that are observed are generally observed only in the short term, so the evidence seldom addresses long-term crime prevention outcomes.
It is important to note here that, in practice, police departments typically implement crime reduction programs that include elements typical of several prevention strategies (as combining elements from multiple strategies may produce more positive outcomes for police agencies). Given this
hybridization of tactics in practice, the committee’s review of the evidence was often hindered by the overlapping character of the real-world proactive policing interventions evaluated in many of the published research studies.
The available research evidence suggests that hot spots policing strategies generate statistically significant crime reduction effects without simply displacing crime into immediately surrounding areas, though there is an absence of evidence on either the long-term impacts of hot spots policing strategies on crime or on possible jurisdictional outcomes (e.g., on crime in a city or in large administrative areas such as precincts). Hot spots policing studies that do measure possible displacement effects tend to find that these programs generate a diffusion of crime control benefits into immediately adjacent areas [Conclusion 4-1].
Another place-based strategy is “predictive policing,” which uses sophisticated computer algorithms to predict changing patterns of future crime. At present, there are insufficient rigorous empirical studies to draw any firm conclusions about either the efficacy of crime prediction software or the effectiveness of associated police operational tactics. It also remains difficult to distinguish a predictive policing approach from hot spots policing [Conclusion 4-2].
A technology relevant to improving police capacity for proactive intervention at specific places is closed circuit television (CCTV), which can be used either passively or proactively. The results from studies examining the introduction of CCTV camera schemes are mixed, but they tend to show modest outcomes in terms of property crime reduction at high-crime places for passive monitoring approaches [Conclusion 4-3]. However, with regard to the proactive use of CCTV, there are insufficient studies to draw conclusions regarding its impact on crime and disorder reduction [Conclusion 4-4].
Despite its popularity as a crime-prevention strategy, there are surprisingly few rigorous program evaluations of problem-oriented policing. Much of the available evaluation evidence consists of non-experimental analyses that find strong associations between problem-oriented interventions and crime reduction. Randomized experimental evaluations generally show smaller, but statistically significant, crime reductions generated by problem-oriented policing programs. Program evaluations also suggest that it is difficult for police officers to fully implement problem-oriented policing. Many problem-oriented policing projects are characterized by weak problem analysis and a lack of non-enforcement responses to targeted problems. Nevertheless, even these limited applications of problem-oriented policing have been shown by rigorous evaluations to generate statistically significant short-term crime prevention impacts. These studies do not address possible jurisdictional impacts of problem-oriented policing and generally do not
assess the long-term impacts of the evaluated interventions on crime and disorder [Conclusion 4-5].
Third party policing, which leverages nonpolice “third parties” (e.g., public housing agencies, property owners, parents, health and building inspectors, and business owners) who are believed to offer significant new resources for preventing crime and disorder, also draws upon the insights of problem solving. Though there are only a small number of program evaluations, the impact of third party policing interventions on crime and disorder has been assessed using randomized controlled trials and rigorous quasi-experimental designs. The available evidence suggests that third party policing generates statistically significant short-term reductions in crime and disorder; there is more limited evidence of long-term impacts. However, little is known about possible jurisdictional outcomes [Conclusion 4-6].
With regard to person-focused interventions, a growing number of quasi-experimental evaluations suggest that focused deterrence programs generate statistically significant short- and long-term areawide crime-reduction impacts. Crime-control impacts have been reported by controlled evaluations testing the effectiveness of focused deterrence programs in reducing gang violence and street crime driven by disorderly drug markets and by non-experimental studies that examine repeat individual offending. It is noteworthy that the size of the effects observed are large, though many of the largest impacts are in studies with evaluation designs that are less rigorous [Conclusion 4-7].
A more controversial person-focused intervention is SQF. Non-experimental evidence regarding the crime-reduction impact of SQF, when implemented as a general citywide crime-control strategy, is mixed [Conclusion 4-8]. A separate body of controlled evaluation research examining the effectiveness of SQF (combined with other self-initiated enforcement activities by officers) in targeting places with serious gun crime problems and focusing on high-risk repeat offenders reports consistent statistically significant short-term crime-reduction effects; jurisdictional impacts, when estimated, are modest. There is an absence of evidence on the long-term impacts of focused uses of SQF on crime [Conclusion 4-9].
The committee also reviewed the crime-prevention impacts of community-based crime-prevention strategies, including community-oriented policing, procedural justice policing (which seeks to impress upon citizens and the wider community that the police exercise their authority in legitimate ways), and broken windows policing. Although a large number of studies of community-oriented policing programs were identified, many of these programs were implemented in tandem with tactics typical of other approaches, such as problem solving. This is not surprising, given that typical implementations of community-oriented policing used by police departments often have included problem solving as a key programmatic
element. The studies also varied in their outcomes, reflecting the broad range of tactics and practices that are included in community-oriented policing programs, and many of the studies were characterized by weak evaluation designs. With these caveats, the committee did not identify a consistent crime-prevention benefit for community-oriented policing programs [Conclusion 4-10].
There is currently only a very small evidence base from which to support conclusions about the impact of procedural justice policing on crime prevention. Existing research does not support a conclusion that procedural justice policing impacts crime or disorder outcomes. At the same time, because the evidence base is small, the committee also cannot conclude that such strategies are ineffective [Conclusion 4-11].
The impacts of broken windows policing are mixed across evaluations, again complicating the ability of the committee to draw strong inferences. However, the available program evaluations suggest that aggressive, misdemeanor arrest–based approaches to control disorder generate small to null impacts on crime [Conclusion 4-12]. In contrast, controlled evaluations of place-based approaches that use problem-solving interventions to reduce social and physical disorder provide evidence of consistent short-term crime-reduction impacts. Little is known about long-term or areawide impacts [Conclusion 4-13].
There is broad recognition that a positive relationship with the police has value in its own right, irrespective of any influence it may have on crime or disorder. Democratic theories assert that the police, as an arm of government, are to serve the community and should be accountable to it in ways that elicit public approval and consent. Given this premise and the recent conflicts between the police and the public, the committee thought it very important to assess the impacts of proactive policing on issues, such as fear of crime, collective efficacy, and community evaluation of police legitimacy.
Place-based, person-focused, and problem-solving interventions are distinct from community-based proactive strategies in that they do not directly seek to engage the public to enhance legitimacy evaluations and cooperation. In this context, the concerns regarding community outcomes for these approaches have often focused not on whether they improve community attitudes toward the police but rather on whether the focus on crime control leads inevitably to declines in positive community attitudes. Community-based strategies, in contrast, specifically seek to reduce fear, increase trust and willingness to intervene in community problems, and increase trust and confidence in the police.
There is only an emerging body of research evaluating the impact of
place-based strategies on community attitudes, including both quasi-experimental and experimental studies. However, the consistency of the findings suggests that place-based proactive policing strategies rarely have negative short-term impacts on community outcomes. (There is virtually no evidence on the long-term and jurisdiction-level impacts of place-based policing on community outcomes.) At the same time, the existing evidence does suggest that such strategies rarely improve community perceptions of the police or other community outcome measures [Conclusion 5-1].
The research literature on community impacts of problem-solving interventions is larger. Although much of the literature relies on quasi-experimental designs, a few well-implemented randomized experiments also provide information on community outcomes. Studies show consistent small-to-moderate positive short-term impacts of problem-solving strategies on community satisfaction with the police; there is very little evidence available on the long-term and jurisdiction-level impacts of problem-solving strategies on community outcomes [Conclusion 5-2]. Because problem-solving strategies are so often implemented in tandem with tactics typical of community-based policing (i.e., community engagement), it is difficult to determine what role the problem-solving aspect plays in community outcomes, compared to the impact of the community engagement element. At the same time, there is little consistency found in problem-solving policing’s impacts on perceived disorder/quality of life, fear of crime, and perceived police legitimacy. However, the near absence of backfire effects in the evaluations of problem-solving strategies suggests that the risk of harmful community effects from problem-solving strategies is low [Conclusion 5-3].
The body of research evaluating the impact of person-focused strategies on community outcomes is relatively small, even in comparison with the evidence base on problem-solving and place-based strategies. (Also, the long-term and jurisdictionwide community consequences of person-focused proactive strategies remain untested.) These studies involve qualitative or correlational designs that make it difficult to draw causal inferences about typical impacts of these strategies. Correlational studies show strong negative associations between exposure to such strategies and the attitudes and orientations of individuals who are the subjects of aggressive law enforcement interventions (SQF and proactive traffic enforcement) [Conclusion 5-4]. The studies that measure the impact on the larger community show a more complicated and unclear pattern of outcomes.
The available empirical research on community-oriented policing’s community effects focuses on citizen perceptions of police performance (in terms of what they do and the consequences for community disorder), satisfaction with police, and perceived legitimacy. The evidence suggests that community-oriented policing contributes modest improvements to the community’s view of policing and the police in the short term. (Very
few studies of community-oriented policing have traced its long-term effects on community outcomes or its jurisdictionwide consequences.) This occurs with greatest consistency for measures of community satisfaction and less so for measures of perceived disorder, fear of crime, and police legitimacy. Evaluations of community-oriented policing rarely find “backfire” effects from the intervention on community attitudes. Hence, the deployment of community-oriented policing as a proactive strategy seems to offer prospects of modest gains at little risk of negative consequences [Conclusions 6-1 and 6-2].
Broken windows policing is often evaluated directly in terms of its short-term crime control impacts. The logic model for broken windows policing seeks to alter the community’s levels of fear and collective efficacy as a method of enhancing community social controls and reducing crime in the long run. While this is a key element of the broken windows policing model, the committee’s review of the evidence found that these outcomes have seldom been examined. The evidence was insufficient to draw any conclusions regarding the impact of broken windows policing on community social controls [Conclusion 6-3]. Studies of the impacts of broken windows policing on fear of crime do not support the model’s claim that such programs will reduce levels of fear in the community, at least in the short run.
While there is a rapidly growing body of research on the community impacts of procedural justice policing, it is difficult to draw causal inferences from these studies. In general, the studies show that perceptions of procedurally just treatment are strongly associated with subjective evaluations of police legitimacy and cooperation with the police. However, the extant research base was insufficient for the committee to draw conclusions about whether procedurally just policing causally influences either perceived legitimacy or cooperation [Conclusion 6-4].
Although this committee finding may appear to be at odds with a growing movement to encourage procedurally just behavior among the police, the committee thinks it is important to stress that a finding that there is insufficient evidence to support the expected outcomes of procedural justice policing is not the same as a finding that such outcomes do not exist. Moreover, although the application of procedural justice to policing is relatively new, there is a more extensive evidence base on procedural justice in social psychology and organizational management, as well as on procedural justice with other legal authorities such as the courts. Those studies are often designed in ways that make causal inferences more compelling, and results in those areas suggest meaningful impacts of procedural justice on legitimacy of the institutions and authorities involved. Thus, the application of procedural justice ideas to policing has promise, although further studies are needed to examine the degree to which the success of such implemen-
tations in other social contexts can be replicated in the arena of policing [Conclusion 6-5].
RACIAL BIAS AND DISPARITIES
Concerns about racial bias loom especially large in discussions of policing. The interest of this report was to assess whether and to what extent proactive policing affects racial disparities in police-citizen encounters and racial bias in police behavior. Recent high-profile incidents of police shootings and abusive police-citizen interaction caught on camera have raised questions regarding basic fairness, racial discrimination, and the excessive use of force of all forms against non-Whites, and especially Blacks, in the United States. In considering these incidents, the committee stresses that the origins of policing in the United States are intimately interwoven with the nation’s history of racial prejudice. When the laws of the United States were designed to produce and maintain racial stratification, it was the job of police officers and sheriff’s deputies to enforce those laws. Beginning in the 1960s and 1970s, as the country moved away from de jure systems of racial hierarchy, law enforcement tactics under the “War on Crime” and “War on Drugs” were characterized, if not by racial prejudice, then by racially disparate consequences. Although in recent decades, police have often made a strong effort to address racially biased behavior, there remain wide disparities in the extent to which non-White people and White people are stopped or arrested by police. Moreover, the U.S. Department of Justice has identified continued racial disparities and biased behavior in policing in a number of major police agencies.
As social norms have evolved to make overt expressions of bigotry less acceptable, psychologists have developed tools to measure more subtle forms of biased behavior. A series of studies in field settings with police suggest that negative racial attitudes may influence police behavior—although there is no direct research on proactive policing. There is a further growing body of research identifying how these psychological mechanisms may affect behavior, and what types of situations, policies, or practices may exacerbate or ameliorate racially biased behaviors. In a number of studies, social psychologists have found that race may affect decision making, especially under situations where time is short and such decisions need to be made quickly. More broadly, social psychologists have identified dispositional (i.e., individual characteristics) and situational and environmental factors that are associated with higher levels of racially biased behavior.
Proactive strategies often facilitate increased officer contact with residents particularly in high-crime areas involve contacts that are often enforcement-oriented and uninvited, and may allow greater officer discretion compared to standard policing models. These elements align with
broad categories of possible risk factors for racially biased behavior by police officers. For example, when contacts involve stops or arrests, police may be put in situations where they have to “think fast” and react quickly. Social psychologists have argued that such situations may be particularly prone to the emergence of what they call “implicit biases.”
Inferring the role of racial animus or other dispositional and situational risk factors in contributing to disparate impacts is a challenging question for research. There are likely to be large racial disparities in the volume and nature of police–citizen encounters when police target high-risk people or high-risk places, as is common in many proactive policing programs (though focused policing approaches may also reduce overall levels of police intrusion) [Conclusion 7-1]. However, studies that benchmark citizen–police interactions against simple population counts or broad measures of criminal activity do not yield conclusive information regarding the potential for racially biased behavior in proactive policing efforts. Identifying an appropriate benchmark would require detailed information on the geography and nature of the proactive strategy, as well as localized knowledge of the relative importance of the problem.
Such benchmarks are not currently available, and existing evidence does not establish conclusively whether and to what extent the racial disparities associated with concentrated person-focused and place-based enforcement are indicators of statistical prediction, racial animus, or other factors that may motivate biased behavior. However, the history of racial justice in the United States, in particular in the area of criminal justice and policing, as well as ethnographic research that has identified disparate impacts of policing on non-White communities, makes the investigation of the causes of racial disparities a key research and policy concern [Conclusion 7-2].
Per the charge to the committee, this report reviewed a relatively narrow area of intersection between race and policing. This focus, though, is nested in a broader societal framework of possible disparities and behavioral biases across a whole array of social contexts. These factors can affect proactive policing in, for example, the distribution of crime in society and the extent of exposure of specific groups to police surveillance and enforcement. However, it was beyond the scope of this study to review them systematically in the context of the committee’s work.
THE FUTURE OF PROACTIVE POLICING
Proactive policing has become a key part of police efforts to do something about crime in the United States. This report supports the general conclusion that there is sufficient scientific evidence to support the adoption of some proactive policing practices, certainly if the primary policy goal is to reduce crime. Proactive policing efforts that focus on high concentra-
tions of crimes at places or among the high-rate subset of offenders, as well as practices that seek to solve specific crime-fostering problems, show consistent evidence of effectiveness without evidence of negative community outcomes. Community-based strategies have also begun to show evidence of improving the relations between the police and public.
At the same time, there are key gaps in the knowledge base. As was discussed earlier, few studies to date have examined long-term outcomes, and there is typically little or no information about the larger areawide or jurisdictional impacts of these approaches. There are also significant gaps in the evidence that do not allow one to identify with reasonable confidence the effects of proactive policing on other outcomes. For example, existing research provides little guidance as to whether police programs to enhance procedural justice will improve community perceptions of police legitimacy or community cooperation with the police. Little is known about the impacts of proactive policing on the legality of police behavior and on racially biased behavior; these are critical issues that must be addressed in future studies.
Much has been learned over the past two decades about proactive policing programs. But, now that scientific support for these approaches has accumulated, it is time for greater investment in understanding what is cost-effective, how such strategies can be maximized to improve the relationships between the police and the public, and how they can be applied in ways that do not lead to violations of the law by the police.