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date: 21 October 2017

Crime Science

Summary and Keywords

Crime science (or more accurately crime and security science) has three core tenets:

• the application of scientific methods

• the study of crime and security problems

• the aim of reducing harm.

Beyond the unifying principles of scientific research (including a clear problem definition, transparency, rigor, and reliability), tools and techniques vary between studies. Rather than following a prescriptive approach, researchers are guided in their selection of data and methods by their research question and context. In this respect, crime scientists take an inclusive view of “evidence.”

“Crime and security” is a broad construct, covering problems associated with diverse illicit goods and acts, offenders, victims/targets, places, technologies, and formal and informal agents of crime control.

Its pragmatic approach distinguishes crime science from “pure research” (i.e., the pursuit of knowledge for its own sake). Contributions to harm reduction might be immediate (e.g., evaluating a novel intervention) or longer term (e.g., building theoretical or empirical knowledge about a particular issue).

Crime science is broad: researchers may contribute to it without self-identifying as crime scientists. Indeed, its early proponents hesitated to draw its parameters, suggesting they should be defined operationally. Under a shared focus on crime, crime science research transcends traditional disciplinary boundaries. The prevalence of multi- and interdisciplinary work reflects the inherent complexity of crime and its control. The social, physical, biological, and computer sciences—and their associated technologies—all have contributions to make.

Although the term crime science was first formalized in 2001, its roots go back much further. Within criminology, it particularly overlaps with environmental and experimental criminology. As well as sharing methods with these two areas, crime science’s theoretical underpinning derives from opportunity theories of crime (e.g., routine activity theory, the rational choice perspective, crime pattern theory). Crime is conceptualized accordingly as primarily non-random and as influenced by both individual criminal propensity and environmental factors that facilitate, promote, or provoke, criminal events.

Crime science techniques have been applied to a variety of issues: primarily volume crimes (e.g., burglary), but also more serious and complex crimes (e.g., terrorism and human trafficking). There is now substantial evidence of the effectiveness of targeted interventions in tackling crimes by manipulating their opportunity structures. Claims that such approaches are unethical and merely cause displacement have been discredited. Crime science now faces other, more challenging criticisms. For example, its theoretical underpinnings are arguably too narrow and the boundaries of the field lack clear distinction. Other challenges include expanding interventions into the online world and resolving tensions around evaluation evidence.

Crime science can clearly help explain and address crime problems. Its focus on outcomes rather than outputs speaks to the growing demand that research be impactful. Evidence generated through robust studies has value for policy and designing primary, secondary and tertiary interventions. In times of austerity and increased focus on multi-agency collaboration, there is a clear audience for crime-related research that can inform targeted responses and speaks to a broader agendum than law enforcement alone.

Keywords: science, environmental criminology, situational crime prevention, experimental criminology, prevention, harm reduction, medical model, opportunity theories, multiagency collaboration, interdisciplinary research, multidisciplinary research

This article covers seven key aspects of crime science. First, the fundamental constructs at the heart of crime science and its distinguishing characteristics are defined. Second, the development of crime science is discussed, together with how it filled a gap in the academic marketplace. This development was not without its critics. Third, key theories underpinning crime science are introduced. Fourth, the practical application of crime science is described, including situational crime prevention and other important principles for the design of crime-reduction initiatives. Fifth, issues to which crime science has been applied and some of the methods used are illustrated. Sixth, the relationships between crime science and other related subjects, such as police science, forensic science, and medical science, are explored. Seventh and finally, some key challenges that crime science faces in the future are raised.

Fundamental Constructs in Crime Science

At its core, crime science involves the application of scientific method, a focus on crime and security problems, and reducing harm.

Science and Scientific Methods

Despite the ubiquity of science in everyday life, its defining characteristics and precise demarcation remain contested (Chalmers, 2013). In this chapter, science is understood in simple and inclusive terms as the systematic and rigorous study of the world and how it works. This definition is reminiscent of a view attributed to Huxley, namely that “science is nothing but trained and organized common sense” (Goldstein & Goldstein, 1984). Although there are certainly flaws in this crude working definition of science (Chalmers, 2013), a more detailed exposition of the history and philosophy of science would be tangential to discussion of crime science. Additionally, Huxley’s conceptualization of science neatly underlines an important point: hypotheses, as tested in science, do not arise in a vacuum, but are formulated by the scientist on the basis of experience, theory, judgment, and common sense.

Given this working definition of science, it follows that scientific methods are simply the approaches and techniques employed in the pursuit of knowledge through science. Crime science is not about reinventing the proverbial wheel, but rather “applying established scientific approaches and techniques to crime control” (Laycock, 2005). Scientific methods evidently comprise a broad and diverse group, incorporating both discipline-specific and transdisciplinary approaches, covering both qualitative and quantitative techniques, and including but not being limited to experimentation and observation. Rather than following a prescriptive approach, crime scientists are (or at least should be) guided in their selection of data and methods by their research question and context.

Despite the heterogeneity of scientific methods, they share certain core principles. Fundamental to science are logic, rationality, clarity in problem definition, the rigorous use of evidence, and transparency, not just in methods, but in explicitly detailing any assumptions and underlying theories. While it is generally a misnomer to claim true objectivity, a scientific approach aims to reduce subjectivity by limiting bias wherever possible and by making its sources explicit. Crime and its control are highly emotionally and politically charged topics. A scientific approach to research is particularly critical in building a solid evidence base that can counterbalance myths, stereotypes, and unsubstantiated popular wisdom.

Previous introductions to crime science have often cited testable propositions (i.e., hypotheses) as a defining characteristic of scientific research (Laycock, 2003, 2005), a view that prioritizes experimentation and quantitative study. This point is worth elaboration. There are contributions to be made to crime science by research in which hypothesis testing is neither appropriate nor valid. Such research could include exploratory, descriptive, and/or qualitative studies and may be particularly pertinent when dealing with understudied and complex crimes. Real world examples include work on radicalization of terrorists and its multilevel causality (Bouhana & Wikstrom, 2011), research into sex trafficking networks as complex systems (Cockbain, 2013a, forthcoming; Cockbain & Wortley, 2015), and investigations into human smuggling (or “snakehead”) organizations (Zhang, 2008; Zhang & Chin, 2002). What these studies are doing, and why they are in the crime science domain, it is argued here, assists in the articulation of “a problem.”

One of the major contributions of scientists is that they ask insightful questions, which are often about challenging a commonly held view of the world. For example, the suggestion in Ancient Greek times that the world was round, rather than flat, represented a radical departure from received wisdom of the time and subsequently took astronomy in a completely different direction. When it comes to crime, being clear on the nature of a problem (and its potential complexity) is a vital first step toward tackling it. Crime scientists recognize that a wide range of analytical approaches can contribute to such problem definition.

The “science” in the term “crime science” not only references the scientific method but also deliberately evokes the physical, social, biological, and computer sciences, all seen as having important contributions to make to crime control (Laycock, 2005). Other fruitful areas for crime science are applied subjects that have a scientific base, such as engineering, architecture, and design. As well as being an inherently multidisciplinary field, crime science also includes individual studies that often transcend disciplinary boundaries (Laycock, 2003). The hard sciences have a key role to play in shaping crime control but the solutions they offer typically benefit from being “tempered by much greater social awareness and sensitivity” (Laycock, 2012). Examples include surveillance technologies like automated facial recognition technology or 3D body scanners. Collaboration between engineers and social scientists on the design and implementation of such new technologies can help ensure that the end-products are not only technically sound but also fit for purpose, in that they are context appropriate, ethical, and practical.

To summarize, crime scientists adopt the scientific method in the study of criminal behavior, the control of crime, and the reduction of associated harms. A wide range of scientific disciplines and subjects is embraced in so doing. A clear role for qualitative and other forms of social science research is recognized in articulating problems of crime and criminality. It would be expected, however, that information so gained would not be seen as an end in itself but as a way of informing experimental or quasi-experimental interventions aimed at reducing harm.


At its simplest, crime is activity that violates criminal law. It is well recognized, however, that crime is a social and moral construct. Its boundaries are heavily influenced by sociopolitical, temporal, and geographical factors—a crime in one jurisdiction now may not be one elsewhere and/or at a different point in time.

A broad view of crime is typically taken in crime science, encompassing a spectrum of activities from commonplace but relatively minor forms of disorder (e.g., littering or noise disturbances) to much rarer but more serious events (e.g., homicide or arms trafficking). This breadth and inclusiveness have led some to prefer the phrase “crime and security science.” For brevity’s sake, the simpler term crime science is used here, but it covers diverse forms of disorder, antisocial behavior, volume crime, organized crime, and even terrorism. Crime scientists might concern themselves with the reduction of harm caused by any one of these activities.

While crime science is distinguished by its broad coverage, individual studies may vary greatly not only in terms of the specific crime(s) addressed but the particular dimension(s) subject to analysis. Examples of such dimensions include illicit goods, services, or acts; offenders; facilitators; victims or targets; places; systems; technologies; specific countermeasures; and diverse formal and informal agents of crime control. Even focusing on a fairly narrow offense, for example, rape, one might find very different types of crime science research, depending on whether the dimension under investigation was:

  • the nature and context of the rape (e.g., familial, acquaintance, or stranger rape; rape in particular settings, such as prisons or schools; male-on-male rape)

  • rapists’ characteristics

  • victims’ characteristics

  • the impact of rape on victims

  • police responses to rape reports

  • the use of DNA evidence in rape investigations

  • geospatial and/or temporal mapping of rape incidents

  • the effects of specific anti-rape interventions

Crime scientists typically take the view that a problem should be specified if crime is to be reduced, detected, or disrupted. Attempts to prevent robbery, for example, would require the crime to be broken down into its various types and interventions to be targeted accordingly. Controlling armed robbery of banks is likely to require a vastly different approach than street robbery of mobile telephones, or robberies at automatic teller machines (ATMs). This is partly because research has shown that the most effective way to prevent crime is to design against it. So, for example, the significant and near global reductions in vehicle-related crime since the 1990s have been directly linked to the redesign of vehicles: the fitting of deadlocks and immobilizers at the point of manufacture (Farrell et al., 2011). Note that this process addresses the target of the offense rather than the offender. There is no evidence that the reduction in vehicle crime was achieved by addressing offenders’ characteristics or somehow deterring, incapacitating, or “treating” them through the criminal justice system. A key aspect setting crime science apart from most traditional research into crime is this focus on crime, not criminality, and offenses, not offenders.

Harm Reduction

Crime science is typically characterized as an applied subject: the end goal is not so much outputs as outcomes (Laycock, 2005). This pragmatic perspective distinguishes crime science from “pure research,” or the pursuit of knowledge for its own sake. Instead, crime science’s focus is on reducing harms caused by crime and security problems. Harm is another broad construct, incorporating loss or damage that may be physical, emotional, financial, reputational, or social. The term reduction is preferred to prevention because it implies an effort to manage crime rather than the idealistic but ultimately unrealistic pursuit of a definitive end to crime.

Within the diverse body of research done under the crime science umbrella, contributions to harm reduction may vary considerably in terms of their immediacy. An evaluation of a new intervention, for example, might generate findings that can be translated promptly into practice and yield fairly immediate crime reduction gains. In contrast, it may take a lot more time, effort, and follow-up research before the findings of exploratory empirical work, or theoretical studies, can be shown to have a clear application to crime control.

The Development of Crime Science

Although crime science was first labeled as such in 2001 (Laycock, 2001a), its roots go back at least 50 years, to the development of ideas regarding crime prevention through environmental design (CPTED; Jeffery, 1971), environmental criminology, and crime analysis more generally. CPTED focuses on the built environment and the extent to which offender behavior can be controlled through its manipulation. Environmental criminology involves the notion that the analysis of crime events can contribute greatly to the understanding and control of crime. It draws heavily on the work of Ronald Clarke, Marcus Felson, and Paul and Patricia Brantingham, although many other scholars have made, and continue to make, significant contributions.

In a seminal paper, Clarke (1983) argued that the immediate environment (“situation”) in which a crime occurs was as important, if not more so, than the offender’s own characteristics (disposition) in affecting crime and hence its control. The so-called situational approach to crime analysis and its prevention, which developed over the following decades, heavily influenced the way crime science was conceived and further developed. It hinges on the notion that immediate opportunities are a necessary condition for the commission of crime. It followed that crime could be reduced by controlling, limiting, or otherwise influencing opportunity structures without recourse to detection, punishment, or attempts to “treat” offenders—many of which had proved elusive and largely ineffectual.

Clark highlighted not only the role of opportunity in crime control but also the relative lack of systematic attention paid by the State to actually preventing crime. The criminal justice system, to which the police were typically seen as the gatekeepers, was almost single-minded about the detection of offending and the treatment of offenders. Treatment should be understood here as encompassing both punishment and individual-change strategies, such as educational or vocational training programs or cognitive, psychiatric, or other medical interventions designed to alter behavior (e.g., sex offender treatment programs or drug/alcohol treatment schemes).

The official view was that crime was best prevented through the criminal justice system, by arrest, prosecution, and treatment. While crime prevention was not entirely absent from official discourse, it was rarely taken very seriously. In the United Kingdom, the police had crime prevention officers whose job it was to encourage the public to take care of their property through the various schemes on offer (e.g., Neighborhood Watch and property marking, both popular in the 1980s). Illustrative of attitudes towards prevention more broadly, crime prevention officers’ activities were not typically seen as “real” police work. The situation in the United States was not dissimilar: even in larger police departments crime prevention was perceived as a highly marginal activity.

The emerging crime scientists saw two serious consequences arising from this approach. First, was the implicit encouragement to delegate responsibility for crime management to the police and the State, rather than to see it as a partnership between law enforcement and the community (Christie, 2000). Second, the enormous contribution to crime control made in practice by the public, industry, and others was effectively downplayed almost to the point of denial. Although the relationship between medical science and crime science is discussed more fully below, it is worth noting here that preventive medicine, in the form of sewers, clean water, and inoculation programs, has made a greater contribution by far to the control of disease than has any intervention(s) delivered once infection or illness has occurred. So too crime prevention, in the form of walls, bank safes, secure transport systems, locks on homes, cars, and other goods and so on, has played a vital role in controlling crime. Without such practical everyday measures, crime rates would surely have escalated beyond all control. It would be foolish indeed to imagine that there would be no crime consequences were all the existing routine preventative measures taken by individuals, communities, organizations, or industries simply discontinued.

A significant part of the perceived need for crime science was to redress this imbalance: to raise the profile of crime reduction, to maintain the argument that opportunities and situational crime prevention have a great deal to offer in crime control, and to re-engage with communities and industries in encouraging their active involvement in reducing crime. Two main points were argued. First, that no other subjects or disciplines were operating in the area of crime reduction. Second, that the way to control crime or reduce the harm it caused required a different set of skills and outlook on crime and criminality than that found in, say, traditional criminology.

Key Theories in Crime Science

Central to crime science is the idea that opportunity plays an important role in explaining, and therefore tackling, crime. In the 1980s and 1990s, opportunity theories represented a radical break with traditional ways of thinking about crime as the inevitable consequence of a criminal “disposition” or individual propensity to offend. In contrast, opportunity theories involve a shift in focus from criminality to crime itself, and treat crime, like any other form of human behavior, as the product of an interaction between disposition and situation (Mischel, 1968; Wortley, 2012). Three theories have been particularly fundamental to the development of crime science and are described in turn here: routine activity theory (Cohen & Felson, 1979; Felson & Eckert, 2015), crime pattern theory (Brantingham & Brantingham, 1984, 1995, 2008), and the rational choice perspective (Cornish & Clarke, 1986).

Routine Activity Theory

Routine activity theory addresses the basic “chemistry” of criminal events. In articulating the theory, Cohen and Felson (1979) proposed that crime has three core ingredients: a motivated offender, a suitable target or victim, and the absence of a capable guardian. Crimes occur, they argued, only when these elements converge in space and time. As a result, crime is not randomly distributed, but instead reflects patterns in the everyday (“routine”) activities of its ingredients. Later additions to routine activity theory include the “intimate handler” (Felson, 1986) and “place manager” (Eck, 1994), figures respectively conceptualized as exerting control over would-be offenders and potential crime locations. The standard articulation of routine activity theory today is captured in the so-called “crime triangle” (or “problem analysis triangle”) shown in Figure 1.

Crime ScienceClick to view larger

Figure 1. The crime triangle (adapted from Clarke and Eck, 2003).

Crime Pattern Theory

Although developed independently of routine activity theory, crime pattern theory (Brantingham & Brantingham, 1984, 1995, 2008) also focuses closely on how everyday activities affect the distribution of criminal events. Crime pattern theory attempts to explain why crime is not randomly distributed, but rather clusters in space and time. A central construct is that of “activity spaces”: zones within which offenders regularly move as they go to work, home, and their social activities. According to the theory, offenders typically identify their targets as they move between these key places (or “nodes”) along their standard routes (or “paths”). Research informed by crime pattern theory tends to focus heavily on the geographical distribution of crime, although the temporal patterns reflecting offenders’ (and victims’/targets’) daily rhythms are of interest too. Given this spatial focus, it is hardly surprising that the analytical technique most closely associated with crime pattern theory is crime mapping.

Rational Choice Perspective

The rational choice perspective positions offenders as rational decision makers (Cornish & Clarke, 1986). Offending is conceived as a purposive action: it meets commonplace needs for sex, status, excitement, money, and the like. Despite its roots in economics, the rational choice perspective is more often associated with qualitative models of decision making than strict mathematical models of cost-benefit analysis (Clarke, 1997a). Offenders are seen as operating with bounded, rather than full, rationality: their decision making is rudimentary and constrained by factors like information deficits, the effects of alcohol consumption, and time pressures (Clarke & Cornish, 1985). Central to the rational choice approach is the premise that scrutinizing the immediate environmental context of an offense provides clues as to offenders’ decision making (Clarke & Felson, 1993; Cornish & Clarke, 1987). At the point of deciding whether or not to commit an offense, the potential offender is said to take into account five factors, namely how (s)he perceives the likely risk, reward and effort associated with the crime, the extent to which the crime can be rationalized or excused, and the level of provocation involved. It follows, therefore, that manipulating the environment to shift implicit cost-benefit analysis to disfavor crime can deter it.

Crime Prevention in Practice

The practical application of crime science includes situational crime prevention, which is introduced here and illustrated with some examples, followed by discussion of the principles to be considered in designing crime reduction interventions.

Situational Crime Prevention

Opportunity theories of crime have proved a rich source of ideas for crime scientists and crime reduction practitioners. Although there are numerous different ways in which crime control may be delivered, the approach most closely associated with crime science is situational crime prevention (Clarke, 1980). At the core of situational crime prevention is the so-called “five pillars” framework (Cornish & Clarke, 2003), a way of conceptualizing the opportunity structures for crime. Crime, it is argued, can be reduced by manipulating the situation to increase risk, to increase effort, to reduce rewards, to remove excuses, or to reduce provocation. Importantly, these factors are not independent: increasing the effort, for example, might lengthen the time required to commit a crime and in so doing increase the associated risk.

The five factors are now seen as major mechanisms through which offending behavior can be reduced (Tilley & Laycock, 2001). The concept of mechanisms draws on the realist perspective (Pawson & Tilley, 1997), a common feature of crime science. The mechanism describes how a crime reduction initiative might exert its effect. In a given context, the intended mechanism may or may not be “fired.” The complex and context-dependent nature of crime has been used to help explain why the same intervention may succeed in one place and time and fail in another (Eck, 2002; Pawson & Tilley, 1997; Tilley, 2006). Realists talk of “context, mechanism, outcome (CMO) configurations,” all of which must be considered when designing a crime control initiative. Based on work by Clarke and Eck (2003), Table 1 sets out key means by which the five mechanisms of situational crime prevention may be achieved.

Table 1. Mechanisms and means by which situational crime prevention goals can be achieved.

Crime prevention mechanism

Means to achieve mechanism

Increase the effort

  1. 1. Target harden

  2. 2. Control access to facilities

  3. 3. Screen exits

  4. 4. Deflect offenders

  5. 5. Control tools/weapons

Increase the risks

  1. 6. Extend guardianship

  2. 7. Assist natural surveillance

  3. 8. Reduce anonymity

  4. 9. Use place managers

  5. 10. Strengthen formal surveillance

Reduce the rewards

  1. 11. Conceal targets

  2. 12. Remove targets

  3. 13. Identify property

  4. 14. Disrupt markets

  5. 15. Deny benefits

Reduce provocations

  1. 16. Reduce frustrations and stress

  2. 17. Avoid disputes

  3. 18. Reduce arousal and temptation

  4. 19. Neutralize peer pressure

  5. 20. Discourage imitation

Remove excuses

  1. 21. Set rules

  2. 22. Post instructions

  3. 23. Alert conscience

  4. 24. Assist compliance

  5. 25. Control drugs and alcohol

Source: Clarke and Eck (2003).

To illustrate the situational approach to crime reduction, consider a hypothetical multilevel car park beset with problems of vandalism and theft of and from motor vehicles. A favored intervention in this context might be the introduction of a closed-circuit television (CCTV) system. The rationale would be that CCTV cameras increase the risk to offenders. There might also be an increase in effort in finding targets not overlooked by the cameras. For the mechanisms to fire, the CCTV must be visible and noticeable. After all, how could it deter offenders if they have not noticed it in the first place? Good signage would therefore be an important component of the intervention. A further advantage is that the signage could help remove excuses for offending by alerting potential offenders’ conscience and setting clear rules. Signage might simultaneously suggest to potential victims that they lock their goods out of sight and lock their doors properly, thereby reducing both provocation and rewards. Firing all these mechanisms should reduce vandalism and theft in the hypothetical car park. Indeed, systematic reviews of the efficacy of CCTV demonstrate the benefits of such an approach (Welsh & Farrington, 2002). Returning to the issue of context, note that there is no evidence that CCTV has a similar effect on reducing public disorder on a Friday or Saturday night in town centers. Offenders in this second context are typically inebriated, inhibiting the deterrent effects of even well-signposted CCTV. CCTV might still be useful in town centers, but for other reasons, such as informing the deployment of police resources after an incident, or supporting detection and prosecution.

Developing crime reduction initiatives is normally carried out as part of a problem-solving exercise. Here, problem solving simply refers to the application of the scientific method. Situational crime prevention projects are a form of action research and typically use a five-stage model (Clarke, 1997a), starting with the articulation of the problem and finishing with an evaluation of the intervention:

  1. 1. Collection and analysis of data about a specific crime issue

  2. 2. Analysis of situational conditions facilitating offending

  3. 3. Identification and assessment of opportunity-reduction measures

  4. 4. Implementation of the measures deemed most promising, practical, cost-effective, and ethical

  5. 5. Evaluation of the effects of the intervention on the problem.

Throughout this process, hypotheses are tested. With a street robbery problem, for example, the initial analysis might involve using recorded crime data to ascertain the precise nature of the problem. The idea might be tested that the observed crime increases were, for example, driven not by a growth in robberies from cash-in-transit vans but by robberies committed by young people against other young people. It might then be suggested that the “real” problem was actually linked to truancy and/or bullying, which would then have implications for the types of responses to be considered.

Other Important Principles in Crime Prevention

Various other principles may usefully be considered in shaping research and crime reduction interventions. Some key examples are briefly outlined here, although the list is certainly not exhaustive.

Crimes Generate Other Crimes

In offending, as in everyday life, one problem often leads to another (Felson & Clarke, 1998). Criminal events can be linked in several different ways. A burglar stumbling upon a home’s occupant, for example, might then choose to commit a physical or sexual assault. After a burglary, further offenses might naturally arise from the processing of the spoils (e.g., handling stolen goods or the fraudulent use of credit cards). If multiple burglars were involved, they might fall out violently over splitting the profits. Furthermore, the commission of certain crimes may be predicated on committing other offenses in preparation (e.g., armed robbery may first require illegally obtaining a weapon and stealing a suitable escape vehicle). Minor offenses may follow from major ones or vice versa (e.g., consider the drug wholesaler who consumes some of his/her product on the side). Links between offenses may be coincidental or causal, such as alcohol-related violence that follows from drunken and disorderly conduct. Finally, there are what Van Dijk (1994) calls “crime chains”: a series of the same offense in which victims offend in retaliation (e.g., bicycle-theft victims’ stealing others’ bicycles in response to their own loss).

Recognizing the interconnectivity of offenses—even those ostensibly very different in nature—is useful in interpreting crime data, prioritizing issues, and estimating levels of harm associated with any given crime. Identifying links between offenses, especially any causal chains, can have important implications for targeting interventions. In combatting alcohol-related violence, for example, resources might be best focused upstream on preventing excessive drinking in known hotspots in the first place.

Crimes Require Certain Facilitating Factors

It has been argued that crime facilitators should be considered a core element of criminal events, just as offenders, victims/targets, and places are (Clarke, 1997b). Facilitators are factors that promote, provoke, or otherwise enable crimes. One way of conceptualizing them is Clarke and Eck’s (2003) distinction between physical, social, and chemical facilitators. Physical facilitators include a burglar’s tools, an armed robber’s weapon, or an abductor’s restraints. Social facilitators encompass interpersonal processes that enable offending, such as rowdy interactions between rival football fans that later escalate into crowd violence or overt machismo among fraternity members that may lead to a permissive attitude toward rape. Chemical facilitators include disinhibitors like alcohol, which is implicated in numerous offenses, ranging from domestic assault to sexual violence. Restricting the availability of facilitators can help tackle crime. Practical examples include the bans in England and Wales on the sale of spray paint to under 16 year-olds and knives to under 18 year-olds, measures designed respectively to reduce graffiti and knife crime.

An alternative but essentially complementary way of looking at facilitators is Ekblom and Tilley’s (2000) idea of “resources for crime.” Resources are a diverse category encompassing both tangible and intangible commodities that influence an individual’s ability and willingness to offend. Ekblom and Tilley classify resources as personal (e.g., strength), cognitive (e.g., knowledge of targets), moral (e.g., neutralization techniques), facilitatory (e.g., weapons), and collaborative (i.e., what is provided by others in one’s criminal network).

Repeat Victimization

Repeat victimization arises when a disproportionately high amount of crime is committed against a small set of targets or victims (Farrell & Pease, 1993). Repeat victimization is a statistical fact, well documented both for crimes in which recurrent attacks on certain victims or targets is self-explanatory (most notably, domestic violence) and those for which it is less obvious (e.g., car theft or burglary). Research since the early 1980s has demonstrated that repeat victimization is a very profitable target for crime reduction efforts (Farrell & Pease, 1993; Forrester, Chatterton, & Pease, 1988; Laycock, 2001b)—it makes good sense to focus on protecting those subject to recurrent offenses—especially in the context of limited resources. Despite this, the importance of repeat victimization is still often overlooked.

Offenders’ Perceptions Matter

If the premise that offending is the product of rational choice is accepted, it follows logically that potential offenders’ perceptions of interventions are critical to their success (Clarke & Eck, 2003). In writing about the failure of legislation and punishment as a means of actually preventing crime, Kennedy (2009) explains how the mechanism of universal deterrence assumed to be at play fails because it rarely corresponds to offenders’ own perceptions of risk and reward. He advocates instead a more targeted approach to deterrence, known as “pulling levers.” Famously used to combat gang-related homicide in Boston, this approach involves scoping a problem to identify the core targets for deterrence and then communicating messages designed to appeal to offenders’ perceptions and priorities through appropriate channels (Kennedy, 2009; Laycock, 2001b). In a similar vein, Ekblom (1997) encourages those designing and deploying situational crime prevention initiatives to “think thief”—to put themselves in the offenders’ shoes and see the world through their eyes. He argues that this may help to anticipate and to avoid unintended consequences of interventions and maximize their chances of success.

Displacement and Diffusion of Benefits

Displacement is an example of an unintended consequence of intervention. Perhaps the most commonly discussed form of displacement is spatial: when the same crime shifts from one location to another. Five further types of displacement have been identified, involving a change in the timing of an offense, the modus operandi, the type of offense, the victims or targets, and the offenders (Barr & Pease, 1990). Displacement has long been a focus for critics of situational crime prevention. In fact, reviews and meta-analyses have shown that displacement is far less likely than generally assumed (Bowers et al., 2011; Hesseling, 1994). Indeed, research has often shown that, rather than displacing crimes to other forms of offending, initiatives can often lead to a diffusion of benefits—a reduction in offending beyond the boundaries of the initiative itself (Clarke & Weisburd, 1994).

Nonetheless, displacement can and does occur. Considering offenders’ perceptions can help identify how certain crime reduction interventions may lead to an escalation in the seriousness of the offense or to some other form of displacement. To illustrate, the introduction of electronic immobilizers into cars has been hailed as the most important contribution to the substantial and sustained decline in car theft seen since the mid-1990s (Laycock, 2001a). Indicating how at least some thieves have adapted their modus operandi to circumvent immobilizers’ preventative effects, concerns have been raised about so-called “car key burglaries” in recent years (Shaw, Smith, & Bond, 2010). Car key burglaries are residential burglaries committed with the specific intention of stealing car keys (and then the car).

Timing is Important

As clichéd as it may be, “nipping problems in the bud” is generally more effective than waiting to act until after they have escalated or become entrenched. So, the timing of interventions is important: both at the level of general crime patterns and at the level of individual victims/targets. In the aggregate, paying close attention to patterns and trends in crime data can help identify emergent problems. The prompt identification of new crime hotspots, “hot products” (frequently targeted goods), or a new modus operandi can inform timely interventions to disrupt, reduce, or detect crimes. At the individual level, the benefits of early intervention are perhaps most pronounced when considering serious interpersonal crimes. A good example is child sexual exploitation. Amid heavy criticisms of the U.K. authorities’ inaction and resultant failure to protect children, there is some (albeit limited) evidence that improved multi-agency collaboration and data-sharing can facilitate early intervention with children at particular risk of being sexually exploited (Beckett et al., 2014; Cockbain, 2013b).

Crime science research can contribute to timely interventions by identifying general patterns underpinning observed crime data. A key example is the growing evidence that burglaries cluster both in space and time. In their work on near repeat victimization, Bowers, Johnson, and Pease (2004) found that when a residential burglary occurs, there is a short window in which other properties in close proximity are at increased risk of being burgled. At a practical level, findings like these can be—and have been—used to target interventions at high-risk properties within a certain time frame.

Developing and deploying effective early interventions require not only that good quality data are collected in the first place but also that they are collated and analyzed effectively and the findings are fed into the tactical and strategic decision-making process. Unfortunately, this is not the case in many police agencies and local authorities in the United Kingdom, a situation no doubt exacerbated by funding cuts and the associated loss of analyst positions (Cope, 2003).

Some Analytical Methods Used in Crime Science

In crime science, as in any scientific endeavor, the domain focus and goals of a given project should determine the selection of a method. In this section, examples are given of a few of the more unusual analytical methods that might be employed in a crime science research project. The list is not exhaustive and featured techniques were selected precisely because they are not necessarily well known or widely understood by those outside the field. Numerous other methods are routinely used in crime science but do not necessarily require the same level of explanation (for e.g., interview- and survey-based techniques of qualitative enquiry, crime mapping using geographical information systems, and various other descriptive and inferential statistical techniques).

Crime Scripting

Initially developed in psychology but now applied across a wide range of fields, a script is a series of actions and decisions that constitute an event. Cornish (1994) introduced crime scripting to crime science as a way of deconstructing specific crimes into their various components so as to identify “pinchpoints” for intervention. Cornish explained the concept through the classic example of the “restaurant script,” behavior associated with dining out: enter the restaurant, take a seat, peruse the menu, order, eat, request the bill, pay the bill, and leave. He argued that just as such strings of actions are replicated across events in the noncriminal world, so, too, offenders employ a common set of behaviors in committing a given offense. To illustrate, a simple crime script for shoplifting might involve entering a shop, selecting a target, checking for surveillance, concealing the good(s), and leaving the premises.

The reason crime scripting is useful is that it exposes potential vulnerabilities in the offending process, which can be blocked, disrupted, or otherwise interrupted. Returning to the shoplifting example, the script highlights that increasing surveillance (e.g., via security guards or CCTV) is just one way of preventing crime. Alternative interventions might include strengthening exit controls (e.g., electronic arches), target hardening (e.g., putting high-value goods in locked cases or behind the counter), and reducing the reward of theft (e.g., security tags on clothing).

There has been considerable variation in the form and content of crime scripts and the crimes to which they have been applied. The common thread is that they deal with the opportunity structures that facilitate offending. The opportunity structures can become complex and very detailed when considering, for example, organized crimes (Hancock & Laycock, 2010), such as cigarette smuggling (von Lampe, 2010) or sex trafficking (Brayley, Cockbain, & Laycock, 2011).

Agent-Based Modeling

Traditionally, studies of spatial patterns in crime have employed top-down approaches, such as geographical mapping of recorded crime data. In contrast, agent-based modeling is a bottom-up approach rapidly gaining popularity in the social sciences (Hill, Johnson, & Borrion, 2014). It involves taking a theoretical model designed to explain a phenomenon, testing it using a computer simulation, and examining the extent to which the behavior thus generated conforms with expectations (Gilbert & Troitzsch, 2005). In short, researchers attempt to “grow” the phenomenon of interest using theoretically grounded computer algorithms (Hill, Johnson, & Borrion, 2014).

The approach has been applied so far to problems including crowd violence (Batty, Desyllas, & Duxbury, 2003a, 2003b), poaching (Hill, Johnson, & Borrion, 2014; Imron, Herzog, & Berger, 2011; Keane, Jones, & Milner-Gulland, 2012), and maritime piracy (Marchione, Johnson, & Wilson, 2014; Vaněk et al., 2013). While the use of simulations in crime science remains fairly novel, its proponents have argued that agent-based modeling can improve understanding of spatial patterns and generate new insights to inform crime control. Another key benefit is that simulations can be built to test the effects of very specific interventions (e.g., increase foot patrol by x% during the hours y to z) (Hill, Johnson, & Borrion, 2014).

Social Network Analysis

Social network analysis involves constructing networks of linked entities (e.g., people or organizations) and analyzing them quantitatively using various metrics. The fundamental premise is that the nature and strength of associations and members’ relational positioning influence both the overall functioning of networks and individual members’ perceptions, capabilities, and activities (Borgatti et al., 2009; McAndrew, 2000). For crime analysis, social network analysis represents a shift in conceptual focus from individual-level attributes of offenders to webs of association (Van der Hulst, 2009). Such connections can be seen as important and previously overlooked opportunity structures for crimes.

Social network analysis can be helpful in informing the gathering of intelligence, detection, disruption, and enforcement (Coles, 2001; Morselli, 2009). For example, it has been demonstrated that less hierarchical and more dispersed networks are much more resilient to enforcement activity targeted at taking out individual members (McAllister, 2004). Social network analyses can also help challenge entrenched misconceptions about organized crime groups: for example, the stereotype that that they form tightly and explicitly structured hierarchies (Morselli, 2009).

Although the literature on social network analysis and crime remains fragmented and underdeveloped, researchers have increasingly argued for its utility in combatting serious crime problems (Morselli, 2009; Schwartz & Rouselle, 2009; Van der Hulst, 2009). Examples of issues to which it has been applied include terrorism (Gill et al., 2014; Pedahzur & Perliger, 2006), drug trafficking (Morselli & Petit, 2007; Natarajan, 2000, 2006), and human trafficking (Campana, 2016; Cockbain, Brayley, & Laycock, 2011 ; Mancuso, 2014).

The Relationships Between Crime Science and Related Approaches

Crime science is particularly closely associated with four other subjects: forensic science, criminology, police science, and medical science. Here, similarities and differences in approach are drawn out and the different perspectives each offers on controlling crime and reducing harm are discussed.

Forensic Science

In simple terms, forensic science is any science used in the criminal justice system (Jackson & Jackson, 2011). In reality, the application of science from a parent discipline to the forensic context may not be straightforward or unproblematic (Morgan & Bull, 2007). Forensic science involves the collection, analysis, interpretation, and presentation of scientific evidence in the context of investigation and prosecution (Jackson & Jackson, 2011). Like crime science, forensic science is inherently multidisciplinary, drawing on concepts, methods, and empirical evidence from diverse fields. Unlike the bulk of the crime science to date, forensic science typically focuses on high-impact, low-volume crimes (e.g., murder, sexual assault).

Forensic science can support the detection of crime and contribute to target-specific prediction, disruption, and prevention. In this respect, it clearly ties in with crime science’s aims and remit. Nonetheless, relevant researchers and practitioners may not necessarily self-identify as crime scientists. There are no clear-cut rules as to which aspects of forensic science are seen as relevant to crime science. One of the clearest overlaps with crime science is how forensic science research is concerned with building and applying a solid empirical evidence base that can inform the robust treatment of evidence throughout the forensic process. One aspect of this is forensic science research into how different trace materials, such as semen (Brayley-Morris et al., 2015), pollen (Morgan et al., 2014), and gunshot residue (French, Morgan, & Davy, 2014), behave in specific environments and under specific conditions. Such research has evident implications for approaches to detection, intelligence gathering, and analysis (Morgan, French, & Meakin, forthcoming).


Criminology is an established social science that has long enjoyed central relevance to issues of crime and policing. It is one of the many—arguably one of the primary—subjects from which crime science draws. Nevertheless, the relationship between the two fields has often been tense, with examples of antagonism from both sides. Leading crime scientist Ron Clarke, for example, dismissed much of criminology’s mission, theory, and methods as irrelevant (Clarke, 2004). Meanwhile, the establishment of crime science was met with skepticism from many criminologists, challenges from some as to why it was needed at all (Loader & Sparks, 2011), and accusations from others that it threatened civil liberties (Garland, 1996; Weiss, 1987).

Given the particularly close relationships between crime science and experimental and environmental criminology, there is a clear risk of overstating the distinction between crime science and criminology. In very simplified terms, factors that are commonly seen to distinguish crime science from traditional criminology include (Loader & Sparks, 2011):

  • a much broader range of sciences on which it draws (the physical, biological, and computer and engineering sciences, as well as the social sciences)

  • a focus on crime rather than criminals or criminality

  • the central importance accorded to opportunity in explaining and tackling crimes

  • concern for immediate crime reduction over long-term reform

  • a general preference for applied over pure research.

Police Science

Crime science is also closely linked to the evidence-based policing movement (Sherman, 1998, 2013), which in turn often centers on the idea of police science (Weisburd & Neyroud, 2011). Crime science and police science have a common core, most obviously their focus on crime and the systematic, rigorous generation of evidence using established techniques. There are also some key differences between the two fields.

First, crime science is more explicitly multidisciplinary and accommodates a broader and more diverse range of methods than police science. Police science’s focus on experimental techniques (especially the randomized control trial) as paramount (Greene, 2014) has led to criticisms of its being dogmatic, reductive, and inadequately matched to the complex realities of crime and the agents of its control (Greene, 2014; Kennedy, 2014; Sparrow, 2011).

Second, police science explicitly focuses on the police as the primary agents of crime control in a way that crime science does not. In doing so, police science implicitly excludes a wide swathe of non-police interventions and other agencies with a formal or informal role in combating crime. This can be seen as limiting, given the “pluralization of policing” (Crawford, 2008): crime control is increasingly acknowledged as going far beyond the State police.

Finally, police science is less explicitly outcome focused than crime science but also deals with certain topics that crime science does not. Examples include police management issues, such as shift patterns, reward structures, and leadership concerns, issues that would typically only concern a crime scientist insofar as they might affect crime reduction.

Medical Science

From its inception, parallels have been drawn between crime science and medical science (Laycock, 2005). Despite the obvious differences in the issues on which they focus, both share a unifying domain focus: reducing harms associated with crime and ill health, respectively. Both draw on a wide range of disciplines to build a coherent and multifaceted knowledge base on complex issues. Some of the contributing disciplines are highlighted in Figure 2, which provides illustrative examples rather than an exhaustive list. Both share a clear commitment to applied research and attempt to formulate ethical, practical solutions to the presenting problems. Medical science is more mature in this respect: ethical behavior is integrated deeply into the professionalization of medicine in a manner not yet fully realized in crime control.

Crime ScienceClick to view larger

Figure 2. Disciplinary contributions to medical science and crime science (adapted and expanded from Laycock, 2005).

The analogy with medical science is particularly helpful in explaining the idea of primary, secondary, and tertiary interventions, which are far more familiar in the context of health care than in crime control. Primary prevention in health care is prevention-focused and covers various routine provisions that reduce the risk of infection, epidemics, and so forth (e.g., drains, sewers, clean water, vaccination programs). Secondary prevention in health care is directed at groups identified as being at high risk (in terms of likelihood or level of harm associated) for particular issues (e.g., influenza vaccinations for elderly or pregnant people, meningitis vaccinations for babies, or diabetes screening tests for Southeast Asians). Finally, tertiary prevention in health care is that provided by general practitioners, hospitals, and the like to those already unwell.

Primary crime prevention is directed at the whole population (e.g., via target-hardening measures like installing immobilizers in cars at the point of production). Secondary prevention is targeted at individuals or locations identified as being at high risk of involvement in crime or already heavily involved. Examples include providing after-school clubs to occupy “at risk” youth or installing CCTV in known theft hotspots. Finally, tertiary prevention operates through the criminal justice system via post hoc confiscation of crime facilitators (e.g., weapons) and treatment of offenders (incarceration alone or active treatment programs). As explained previously, the establishment of crime science was focused on raising the profile of primary prevention as a means of combating crime. Today, other approaches are increasingly accommodated as well, in particular those related to secondary prevention.

In many ways, the so-called “medical model has come to represent an aspiration for what should be a thorough orientation of policing toward effective evidence-based practice” (Kennedy, 2014). Although few would disagree with the fundamental aim of better integrating research into policy and practice, it is possible to take the analogy with medicine too far. Critics have cautioned against overstating the model’s goodness of fit to policing and crime control. In particular, they have questioned the ensuing focus on randomized control trials as the primary—even exclusive—source of evaluation evidence and the implicit assumption that policing is at a level of professional development comparable to that of medicine (Kennedy, 2014; Sparrow, 2011). Indeed, the most relevant methodological approach for the crime scientist is arguably engineering, where initiatives (or products) are developed on the basis of theory and are tested and modified in the light of observations following implementation.

The Future of Crime Science

Crime science has made striking progress since its formulation in the early 2000s. In just over a decade, it has gone from being an unknown upstart to a recognized and respected approach in conceptualizing, analyzing, and responding to crime. As with anything new, there have inevitably been glitches along the way. Rather than dwell here on criticisms of crime science that have long been discredited (e.g., that its interventions are invariably unethical and ineffective) or discuss what might have been done differently in hindsight, the focus here is the future. It is argued that the fruitful development of crime science requires further barriers and challenges to be overcome. Six key issues for consideration are identified and briefly discussed.

Successfully Straddling Disciplinary Boundaries

The manner in which teaching, research, and other operations are conducted within universities creates academic silos (Pease, 2005). While this is necessary to the efficient overall operation of the organizations and has evident advantages over some sort of academic anarchy, it comes at a price. The ensuing silos are not only organizational or disciplinary in nature but also silos of thought. Silos are unhelpful when addressing the complex problems of modern societies, such as the control of crime.

In developing crime science as an approach, deliberate attempts were made to break down the silos of thought. Crime science is not a discipline in the strictest sense, but rather a transdisciplinary hybrid that straddles multiple fields. Beyond a unifying focus on crime and opportunity theories, its research draws on a sometimes staggering array of theories, analytical techniques, and empirical evidence. On the positive side, this diversity translates into a vibrant body of research and considerable flexibility in addressing the demands of particular problems. There is a danger, however, that crime science’s development may be hampered by difficulties in securing funding for truly interdisciplinary work, a lack of consistency and coherence across its empirical and theoretical research base, and perhaps even difficulties in identifying relevant research (or relevant researchers not self-identifying as crime scientists).

Further Expanding Crime Science’s Contribution to Dealing with Organized Crime

In theory, crime scientists might deal with virtually any crime, disorder, or security problem. In reality, the bulk of the literature has focused on “volume crime”: relatively high-frequency but low-harm problems like burglary or vandalism (Bullock, Clarke, & Tilley, 2010a). More serious and organized crimes have long been neglected. Various factors might have contributed to this imbalance, including data availability, prioritization of issues, or simply greater resistance to the idea that opportunity might be a key driver behind serious crimes.

The situation is slowly changing but more needs to be done to reduce the perception that crime science is just about volume crime. One form of low-frequency, high-harm crime into which crime scientists have made modest but notable in-roads is child sexual abuse. Long assumed to be a unique and inexplicable phenomenon (Wortley & Smallbone, 2012), child sexual abuse research and responses have traditionally been dominated by a dispositional outlook that prioritizes individual offenders’ psychopathology and their treatment (Wortley & Smallbone, 2006). Under the pioneering influence of Smallbone and Wortley, there has been a marked increase in situational research into child sexual abuse (Cockbain & Reynald, 2016). In turn, new and potentially promising avenues for intervention are slowly opening (Wortley & Smallbone, 2006, 2012). Similar developments are afoot with the gradual expansion of the crime science approach into other forms of serious and organized crime, such as terrorism, human trafficking, and wildlife crime (Bullock, Clarke, & Tilley, 2010b; Freilich & Newman, 2009; Lemieux, 2014).

Improving Design Against Virtual Crime

The power of good design is now recognized as playing a major role in crime reduction, as is the contribution to such design made by engineers, designers, computer scientists, and many others. The crime drop seen in many countries over the past two decades or so is now reliably attributed to situational changes resulting from advances in technology and design changes (Farrell et al., 2010, 2011).

The application of design against crime in the virtual world lags far behind the offline world. Yet, the proliferation of the Internet has evidently created enormous opportunities both for new offenses and for committing old offenses in new ways. Crimes that have shifted online and cause great concern include fraud, the distribution of indecent images of children, and the recruitment and radicalization of terrorists.

Traditional enforcement-led crime control is often stymied by offenses that transcend national borders and jurisdictions. Even when international collaboration works well, it can be expensive, difficult, and time consuming to manage transnational investigations and prosecutions. There is clear and largely untapped potential for crime scientists to contribute to the control of Internet-enabled crime through improved problem analysis and the development of targeted interventions. Such interventions might include hardware, software, and wetware (human) solutions.

Reintegrating the Social Side to Situations

The formalization of situational theories of crime was followed by a period of self-imposed segregation (Clarke, 1997b). Such segregation was arguably necessary in order to establish the situational approach and distance it from traditional criminology and its dominant foci. A consequence for crime science, drawing as it does on situational approaches, has been a disproportionate focus on the physical environment at the expense of the social (Andresen & Felson, 2010). It has been contended that this imbalance limits the explanatory and preventative utility of much situational research (Andresen & Felson, 2010).

Crime science would now benefit from greater attention to the immediate social elements to opportunity structures for crime, including interpersonal dynamics, co-offending and offender networking. Such developments are happening but remain fairly marginal. Yet, it is increasingly recognised that social processes influence offenders’ (and victims’) perceptions, beliefs, actions and reactions (Andresen & Felson, 2010; Kennedy, 2009; Wortley & Mazerolle, 2008). For example, associations have been documented between co-offending (criminal collaboration) and involvement both in more prolific offending and committing more serious offenses (Andresen & Felson, 2009, 2010, 2012; Felson, 2003). In seeking to become more “social,” crime science could benefit from greater interdisciplinary exchange with social psychology. The two approaches share a keen recognition of situations’ power in shaping human behavior (Mischel, 1968).

Making Sense of Big Data

The generation and collection of ever-increasing amounts of “big data” have the potential to inform crime analysis and intervention. The criminal justice system has long been criticized for an overwhelmingly reactive approach to crime control, epitomized in the traditional focus on investigation, prosecution, and treatment. More efficient capture, collation, and interrogation of big data could help improve early intervention and crime reduction and could facilitate genuinely predictive policing. Crime scientists have a clear role to play in exploring how large volumes of data and/or data from across different systems can be used to improve crime control.

Researchers can contribute, too, in the development of processes and software to manage crime-related data. For example, police investigating child sexual abuse today may retrieve millions of indecent images of children when searching the computer of a single suspect. Research might usefully inform how further investigation is prioritized, safeguarding interventions are deployed, and the processing of such files is automated. To give a very different example, banks currently report to the authorities suspicious activity—as defined by a set of agreed parameters—and employ proprietary algorithms to detect fraud. Crime scientists might investigate whether empirically and theoretically informed algorithms could be developed to detect concerns about other specific criminal activities from individuals’ routine financial transactions. Often, such projects will require not only a mix of disciplinary skills and experiences but also close collaboration with industry partners and end-users.

Working Out “What Works”

As has been highlighted in this article, crime science is avowedly outcome focused. It is intended to inform crime-related policy and practice and thus reduce harms. Consequently, deciding upon “what works” in crime reduction is an area of central concern to crime science. If crime is to be controlled as far as is reasonably possible in a capitalist State, then the police, government, industry, and civil society need to know not only what to do but where and when to do it and why it might work.

Recent years have seen a marked increase in appetite for expanding the knowledge base on evaluations and their effectiveness. This is reflected in a growth in research activity around systematic reviews and, in the United Kingdom, a multimillion pound investment into a “What Works Centre for Crime Reduction.”

A key challenge facing crime scientists is managing—and ideally resolving—tensions that have arisen in the “what works” field. On the one hand, there are the evaluation purists who prioritize experimental and quasi-experimental evidence, sometimes to the exclusion of all else (Sherman, 2013). On the other hand, the evaluation realists argue that consideration must be paid not just to the end results (what works) but to the mechanisms (when, where, how it works) by which they are achieved (Tilley & Laycock, 2001). If common ground cannot be found, there is a very real risk that crime control efforts will be damaged by conflict between the two approaches.

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