Marc L Swatt. 21st Century Criminology: A Reference Handbook. Editor: J Mitchell Miller. 2009. Sage Publications.
Crime is not a random event. Criminological research suggests that certain psychological, social, or economic characteristics are associated with higher levels of criminal involvement. Furthermore, particular lifestyles and patterns of activity place individuals at a heightened risk for victimization. Crime fluctuates temporally as well: More crimes occur in the evening as opposed to the morning, on weekends as opposed to weekdays, and in summer months as opposed to winter months. It comes as no surprise that spatial patterns of crime exist as well. For example, Sherman and colleagues (Sherman, Gartin, & Buerger, 1989) found that approximately 50% of calls for service came from approximately 3% of addresses in Minneapolis, Minnesota.
Crime mapping is the process through which crime analysts and researchers use location information about crime events to detect spatial patterns in criminal activity. Early crime mapping efforts typically involved placing physical markers, such as pins, on maps to designate the locations where crimes occurred. Patterns of criminal activity were determined primarily through visual inspection of these maps. With the advances in computing, geographic information system (GIS) software, such as MapInfo and ArcGIS, enables researchers to convert geographic information (addresses or global positioning system [GPS] coordinates) into coordinates used with virtual maps. Researchers and crime analysts can then use a number of analytic software packages to examine and detect patterns of criminal activity from these virtual maps.
This chapter is designed to offer an overview of the field of crime mapping. First, the history of crime mapping is briefly discussed. After this, a brief overview of several theoretical perspectives that have been used to understand the spatial patterns of crime is provided. Following this, some of the major findings in spatial crime analyses are discussed, particularly in regard to the relevance of implementation strategies designed to combat crime. The chapter concludes with recommendations for future directions in crime mapping research.
A Brief History of Crime Mapping
Interestingly, the earliest efforts at crime mapping can be traced to the roots of the discipline of criminology itself. In the early 19th century, a number of studies examined the distribution of crime in France and England. Brantingham and Brantingham (1991a) provided an overview of some of the findings of the main studies from this era. Guerry and Quetelet mapped crimes in France at the department level and found that crimes were not distributed evenly across departments. They also found that there was stability over time in both areas with high crime and areas with low crime over time. These findings were echoed in England with studies by Plint, Glyde, and Mayhew.
In the United States, Shaw and McKay’s (1942) seminal study of juvenile delinquency in Chicago made extensive use of crime maps. Shaw and McKay borrowed Park and Burgess’s (1924) ecological model and divided the city into five different zones. They found that the zone adjacent to the central business district, the zone of transition, perpetually suffered from the highest rates of juvenile delinquency and other social problems regardless of the specific ethnic group occupying the zone at the time. This research was instrumental in popularizing social disorganization theory and inspired a number of similar mapping projects in Chicago; Philadelphia; Richmond, Virginia; Cleveland, Ohio; Birmingham, Alabama; Denver, Colorado; Seattle, Washington; and other cities.
Accompanying these early efforts in crime mapping were developments in the profession of policing that provided additional opportunities for crime mapping. In the late 19th and early 20th centuries, the professionalization movement in policing encouraged police organizations to compile statistics documenting the extent of crime in their jurisdictions. In fact, one of the main justifications for the creation of Federal Bureau of Investigation was for the explicit purpose of documenting the extent of crime in the United States through the Uniform Crime Reporting program (Mosher, Miethe, & Phillips, 2002). During this time, many agencies began compiling crime statistics and conducting analyses of crime data. Crime mapping was primarily done using pin maps, which were very time-consuming and provided only a basic visualization of crime patterns.
The late 1960s and early 1970s were critical for the development of crime mapping. In 1966, the Harvard Lab for Computer Graphics and Spatial Analysis developed SYMAP (Synagraphic Mapping System), one of the first widely distributed computerized mapping software programs. The Environmental Science and Research Institute was founded in 1969 and in the subsequent decades emerged as one of the top distributors of GIS software, including the current ArcView and ArcGIS software packages. Also around this time, the U.S. Census Bureau began the ambitious GBF-DIME (Geographic Base Files and Dual Independent Map Encoding) project, which was used to create digitized street maps for all cities in the United States during the 1970 census (Mark, Chrisman, Frank, McHaffie, & Pickles, 1997). These advances were necessary for the development of GIS programs used in crime mapping.
The use of GIS programs for mapping has been the most important advance in the field of crime mapping. There are several important advantages in using virtual maps instead of physical maps. First, computers have dramatically reduced the time and effort required to produce crime maps. Given the relatively low cost and user-friendliness of many of these software programs, it no longer requires a substantial investment for agencies that wish to engage in crime mapping. Second, these GIS programs reduce the amount of error associated with assigning geographic coordinates to crime events. Third, virtual maps are much more flexible than physical maps, allowing researchers and crime analysts to compare the geographic distribution of crimes against other characteristics of the area under investigation (e.g., census bureau information, city planning and zoning maps, and maps produced by other agencies). Finally, GIS and other spatial analysis software provide powerful statistical tools for analyzing and detecting patterns of criminal activity that cannot be detected through simple visual inspection.
In the mid-1970s and early 1980s, a crisis of confidence in traditional police practices emerged following the results of studies, such as the Kansas City Preventative Patrol experiment, that suggested that the police were not effective in combating crime (Weisburd & Lum, 2005). Goldstein’s (1979) problem-oriented policing emerged as a response to this crisis and emphasized that policing should involve identifying emerging crime and disorder problems and working to address the underlying causes of these problems. Academic interests in the field of criminology also began to shift during this time. While many criminologists were concerned with causes of crime that were outside the sphere of influence of police agencies (e.g., economic depravation, differential association, and social bonds), a number of researchers, such as Jeffery (1971), Newman (1972), and Cohen and Felson (1979), began discussing factors that contribute to the occurrence of crime that were more amenable to intervention. The combination of the shift in theoretical focus in criminology and the shift in the philosophy of policing yielded new opportunities for crime mapping and initiated a resurgence of research on both the geography of crime as well as crime prevention strategies involving crime mapping.
Although the first instances of computerized crime mapping occurred in the mid-1960s in St. Louis, Missouri, the adoption of computerized crime mapping across the United States remained relatively slow. Although a number of agencies, in particular in larger jurisdictions, became early adopters of computerized crime mapping technology, the large period of growth in computerized crime mapping did not begin until the late 1980s and early 1990s (Weisburd & Lum, 2005). The rate of adoption of crime mapping among departments greatly increased as desktop computers became cheaper and more powerful and GIS software became easier to use and more powerful. The Compstat program, which started in 1994 in New York City, emphasized crime mapping as a central component to strategic police planning and helped popularize crime mapping among police agencies. With assistance from the Office of Community Oriented Police Services and the National Institute of Justice, a large number of departments adopted computerized crime mapping practices. By 1997, approximately 35% of departments with more than 100 officers reported using crime mapping (Weisburd & Lum, 2005).
Theoretical Perspectives in Crime Mapping Research
As previously noted, the development of tools and techniques of crime mapping have been accompanied by an expanding body of criminological theory oriented toward explaining the geographic patterns of crime. It is important, when discussing theories about the spatial distribution of crime, to distinguish between theories that explain criminality and theories that explain criminal events. Traditional criminological approaches tend to emphasize individual level social and psychological characteristics as the main factors that lead to criminality, that is, the propensity toward committing criminal acts. These theories focus predominately on explaining why offenders engage and persist in criminal lifestyles. Alternatively, theories that discuss the spatial distribution of crime focus on explaining the patterns seen in criminal events, that is, the occurrences of crime. These theories focus less attention on the motivations of offenders and more attention on factors of the environment that promote crime.
Social Disorganization Theory
Although a number of theories have been proposed to explain why particular neighborhoods experience high crime rates, social disorganization theory has been the most influential. Social disorganization theory, as first proposed by Shaw and McKay (1942), can be seen as the first attempt to construct a criminological theory of place. The concept of social disorganization refers to “the inability of local communities to realize the common values of their residents or solve commonly experienced problems” (Bursik, 1988, p. 521). As such, disorganized communities suffer from diminished capacities to exercise social control and are unable to regulate the behavior of community members (see Bursik & Grasmick, 1993). As the capacity of a community to regulate the behavior of its members decreases, the potential for illegal activity increases.
A central tenet of social disorganization theory is that structural conditions within a neighborhood attenuate the social ties that promote social cohesion and enable community members to exercise social control. Economic depravation creates undesirable living conditions that promote residential instability and population heterogeneity. Because social ties require time to form, high residential instability in neighborhoods prevents the development of social ties as residents frequently relocate (Bursik & Grasmick, 1993). In neighborhoods with high levels of population heterogeneity the extensiveness of friendship and acquaintance networks through which social control is exercised is limited because of social and cultural barriers between residents (Bursik & Grasmick, 1993). Structural factors such as these compromise the social integration of neighborhood residents and undermine perceptions of collective efficacy, that is, the collective sense of trust, social cohesion, and willingness to intervene on behalf of the public good (Sampson, Raudenbush, & Earls, 1997). Neighborhoods that have low collective efficacy are likely to experience high levels of crime.
Routine Activities Theory
Cohen and Felson’s (1979) routine activities theory has been applied extensively to research on spatial patterns of crime. To Cohen and Felson, crime is a predatory activity and, as such, can subsist only near patterns of legitimate activity. Therefore, to understand crime patterns it is necessary to understand the patterns of conventional routine activities around which crime is organized. Criminal victimization occurs where routine activities produce a convergence in space and time of the three necessary conditions for crime to occur: (1) a suitable target, (2) a motivated offender, and (3) the absence of capable guardians (Cohen & Felson, 1979). Felson (1998) explained that suitable targets have value to the offender, are visible to the offender, are easily moved or removed, and are accessible by the offender. The concept of guardianship has also been extended and includes intimate handlers, who are responsible for monitoring the behavior of offenders; guardians, who are responsible for protecting targets; and place managers, who are responsible for monitoring and controlling access to particular spaces (see Eck, 2001). In applications of this theory to spatial crime analysis, structural features of the city, patterns of land use, and the routine activities associated with particular locations can concentrate motivated offenders and suitable targets into areas with limited guardianship. This, in turn, fosters opportunities for criminal victimization.
Crime Prevention through Environmental Design and Defensible Space Theories
A couple of important theories have been proposed to explain why criminal events occur more frequently at particular sites. Jeffery (1971) was one of the first criminologists to suggest that immediate features of the environment affected crime, with his Crime Prevention Through Environmental Design (CPTED) approach. This approach emphasizes target hardening and surveillance. Contemporaneously, Newman (1972) also emphasized the role of the environment in creating crime with his defensible space theory. Newman argued, in regard to public housing, that it is possible to design the use of space to enhance territorial functioning and to improve the natural surveillance in these environments. Crowe (2000) expanded on both Jefferey’s and Newman’s initial theories. In the current formulation of CPTED, Crowe discussed three strategies that are used to prevent crime: (1) access control to prevent contact between the offender and the target, (2) surveillance to monitor areas and discourage offenders, and (3) territorial reinforcement to promote feelings of ownership among users of the space. CPTED is usually employed along with situational crime prevention (discussed in the next section) to formulate practical strategies for reducing crime.
Rational Choice Perspective and Situational Crime Prevention
The rational choice perspective (Cornish & Clarke, 1986) is primarily concerned with understanding offender decision making. This approach assumes that offenders possess limited rationality, meaning that they make rational calculations of the costs and benefits associated with crime but are constrained in their decision making by time, information, context, ability, and prior experiences. This perspective seeks to understand the series of decisions made by the offender that result in a criminal event. Interestingly, unlike many other theories of offending, the rational choice perspective emphasizes that different decisions are involved in the production of different types of crime. Rational choice explanations of criminal offending differ by crime type, instead of ignoring these differences in favor of a general motivation toward engaging in crime, as is common in many other criminological theories. Spatial applications of the rational choice perspective emphasize offender movement, search patterns, and target selection processes that determine the spatial patterns observed in crime.
Situational crime prevention (Clarke, 1997) refers to the application of the rational choice perspective toward developing policy recommendations to reduce crime. Situational crime prevention emphasizes situational-level interventions toward increasing the efforts associated with committing a crime, increasing the perceived risks for engaging in crime, reducing the anticipated rewards from crime, and removing the excuses associated with crime (Clarke, 1997). As with the CPTED and defensible space theories, the policy applications of situational crime prevention focus on practical strategies that are customized to specific settings. Although the successes of this approach are well documented, rarely do the methods used in these studies permit broad conclusions regarding the effectiveness of this approach at reducing crime (see Clarke, 1997, for a discussion).
Crime Pattern Theory
Brantingham and Brantingham (1991b, 1993) developed a perspective referred to as crime pattern theory that incorporates elements of the rational choice, routine activities, and other spatial perspectives on crime. According to this perspective, individuals create a cognitive map of their spatial environment with which they are familiar through their routine activities. The action space of an individual consists of (a) nodes, the destinations of travel, such as work, home, and entertainment locations, and (b) paths, the travel routes that individuals take to move from one node to another. Through repeated movement along paths to various nodes, individuals develop an awareness space consisting of the areas in a city with which they are familiar. According to this theory, offenders search for suitable targets primarily within this awareness space by comparing potential targets against templates, or mental conceptualizations of the characteristics of appropriate targets. The likelihood of a particular target being selected by an offender dramatically decreases as an offender moves away from his or her awareness space, a process often referred to as distance decay (see Rengert, Piquero, & Jones, 1999). One interesting application of this theory is geographic profiling, which attempts to narrow the scope of police investigations by using information on repeated crimes to identify the awareness space of a repeat criminal (see Rossmo, 2000).
Spatial Crime Research and Planning Interventions
As previously indicated, a large number of studies have demonstrated that criminal events are spatially concentrated. Although the extent of concentration differs between studies, all empirical evidence suggests that a small number of places account for the majority of crime within any given city. Sherman and colleagues (1989) popularized the term hot spot to describe these areas where crime is concentrated. The detection and explanation of these hot spots is a major concern of research in crime mapping. Hot-spot analysis is currently very popular among police agencies because it provides a method to coordinate interventions in emerging problem areas.
A number of studies have demonstrated the benefits of hot-spot analysis to help coordinate police responses to crime. For example, in a randomized experiment in Minneapolis, Sherman and Weisburd (1995) found that concentrated patrol efforts in hot-spot areas produced a significant decline in calls for service. Police responses to crime are not limited to enhanced patrol. In another randomized experiment in Jersey City, New Jersey, Weisburd and Green (1995) found that after identifying drug market hot spots using crime mapping, a coordinated policy of engaging business owners and community members coupled with police crackdowns yielded substantial decreases in disorder calls for service. In fact, a recently conducted meta-analysis on street-level drug enforcement indicated that approaches that focus on community–police partnerships in drug market hot spots were more effective than enforcement-only approaches (Mazerolle, Soole, & Rombouts, 2006). This suggests that the best approach is a coordinated strategy between police officers and community members toward reducing crime in identified hot spots.
Community-Level Factors Affecting Crime
When designing strategies to address crime in hot-spot areas, it is important to consider the community context that contributes to emergence and maintenance of hot spots. Neighborhood-level research on spatial crime patterns helps illuminate the factors associated with heightened levels of crime. As previously mentioned, economic depravation, residential mobility, and population heterogeneity all contribute to higher levels of crime in a neighborhood by impeding the development of social ties between residents (Bursik & Grasmick, 1993). Family dissolution and inadequate supervision of adolescents also contribute to increased levels of crime. In fact, the presence of unsupervised adolescents in a community is an important predictor of violent crime in a neighborhood (Veysey & Messner, 1999). Rose and Clear (1998) suggested that prior crime policies that result in mass incarceration may also impair community functioning, because in some communities this represents a substantial loss in the social and human capital on which informal social control depends.
Although many of the structural factors contributing to social disorganization remain outside the control of police agencies, such as concentrated disadvantage and high residential mobility, it remains possible to design interventions to increase social integration and improve collective efficacy. Community policing emphasizes community involvement in responding to crime problems through the creation of police–community partnerships, which should both increase community access to public social control and foster improved trust between community members and police officers. Furthermore, programs designed to increase community integration through increasing resident involvement in local agencies should be helpful in fostering the development of social ties and increasing perceptions of collective efficacy. Finally, if Rose and Clear (1998) are correct, community corrections and offender reintegration efforts should alleviate some of the impact of the mass incarceration policies that have removed offenders from the community. Bursik and Grasmick (1993) provided an extensive discussion on various community-based interventions and provided suggestions for how to improve these programs.
In addition to the previously discussed factors, a fair amount of research has examined the effects of incivilities on crime and the fear of crime within a community. Incivilities, such as poorly tended residences, the accumulation of refuse, graffiti, and public loitering and drunkenness, are signs of disorder. A number of studies have demonstrated that the presence of incivilities in a neighborhood is associated with increased levels of serious crime and with heightened fear of crime among community residents (see Skogan, 1990). Sampson and colleagues (1997), however, suggested that this relationship is spurious and that crime and incivilities result from the same underlying causal process, namely, a lack of collective efficacy. Although the causal role of incivilities in producing crime is in doubt, they may still function as leading indicators of potential crime problems, meaning that mapping incivilities may provide information on communities where hot spots may be emerging.
City Features and Crime Locations
In truly comprehensive strategies for addressing crime in hot-spot areas, it is important not only to examine neighborhood-level factors that contribute to the emergence of a crime hot spot but also to consider microlevel place characteristics that promote crime. As Sherman and colleagues (1989) noted, even within high-crime neighborhoods there is substantial variability in the levels of crime. Some places within these neighborhoods experience very low levels of crime, whereas other places are responsible for a substantial amount of the crime.
A number of studies have demonstrated that hot spots of crime tend to emerge around particular features of the urban environment, such as bars and taverns (Roncek & Maier, 1993), fast food restaurants (Brantingham & Brantingham, 1982), schools (Roncek & Faggiani, 1985), public housing (Roncek, Bell, & Francik, 1981), vacant buildings (Spelman, 1993), and public transportation (Block & Davis, 1996). These locations may promote crime by juxtaposing motivated offenders and suitable targets in the absence of capable guardians. Furthermore, the pattern and timing of criminal events in these areas follow the rhythm of legitimate social activity in these areas. For example, crime around bars is more common during evenings and weekends, because more legitimate patrons visit bars during this time. Crime is more common around schools during the school year and after school, because many students interact at this time near school grounds without teacher or parental supervision. Understanding the relationship between the pattern of legitimate social activity and criminal activity around these areas allows researchers and policymakers to design suitable crime prevention strategies.
In addition to identifying the location and timing of criminal events at particular sites, it is important to discern the mechanism through which these areas produce criminal opportunities. Brantingham and Brantingham (1993) discussed the differences between crime generators and crime attractors. Crime generators, such as transit stations, foster criminal activity by bringing both victims and offenders into a location. On the other hand, crime attractors, such as bars and taverns, tend to bring higher proportions of offenders into an area because these locations are tied to patterns of illicit activity. It is important to discern whether a given location functions as a crime generator or a crime attractor, because the appropriateness and effectiveness of intervention strategies may differ by type of location.
There is no shortage of practical policy recommendations for reducing or eliminating criminal opportunities around hot-spot areas. Clarke’s (1997) situational crime prevention model offers a set of 16 different opportunity-reducing strategies. Among those most applicable to location-based interventions are controlling access and entry/exit screening; improving surveillance by officers, civilians, and citizens; deflecting offenders by disrupting routines that promote crime; and facilitating compliance with rules. Use of these strategies to control opportunities for crime may help reduce the risks of victimization in hot-spot areas.
Unanticipated consequences are always a concern when designing an intervention. For interventions in crime hot spots, crime displacement is of particular importance. After the intervention is implemented and crime opportunities are reduced, it is possible that offenders simply relocate their activities to areas outside the intervention site. For example, if a police crackdown on drug trafficking is initiated at a particular intersection that is a hot spot for drug dealing, it is possible that offenders will simply move to a nearby intersection, and drug sales will continue. Other types of crime displacement, such as offenders committing crime during different times, offenders selecting different targets, or even offenders committing different types of crimes, also are possible. Given the wide ranges of different responses that might constitute crime displacement, it is difficult to conclusively demonstrate that crime displacement did not occur during a particular study. For this reason, any researchers or policymakers implementing place-based intervention strategies should be keen to the possibility of crime displacement. Fortunately, the empirical literature on crime displacement is decidedly mixed, and it appears that many interventions do not lead to appreciable crime displacement effects (see Clarke, 1997, for a discussion).
Future Directions and Challenges in Crime Mapping
On the basis of the current research on the spatial patterns of crime, a number of avenues of research in crime mapping are worth exploring. Obviously, a major focus for future research in this area will be further development and refinement of the tools needed in crime mapping studies. Although not discussed in this chapter, there are substantial methodological and analytic difficulties that remain in crime mapping research. Beyond this, however, there are a number of substantive research avenues in crime mapping that are worth pursuing.
A first avenue of research is the further development and integration of theories of the spatial distribution of crime. Although there have been some efforts at integrating social disorganization and routine activities theories (see Miethe & Meier, 1994), additional work remains. These theories share considerable conceptual overlap, and linking the two should provide a more comprehensive framework for understanding the relationship between crime at the macroand microlevels. Furthermore, the criminal events perspective (Meier, Kennedy, & Sacco, 2001; Sacco & Kennedy, 2002) provides a mechanism to link other theories of criminality with theories of criminal events. To date, the implications of other theories of criminality for understanding the spatial distribution of crime remains unexplored and may provide useful insights into offender search patterns and the selection of targets and locations.
A second area of research that would be very helpful in regard to policymakers is expanding crime mapping to include additional justice agencies. The vast majority of research in crime mapping has used calls for service and crime report data, and most applications of crime mapping have been applied to police decision making. Researchers should consider broadening the scope of crime mapping efforts to incorporate data from other justice agencies. In a practical sense, mapping efforts involving other agencies can provide assistance with managing caseloads and coordinating the distribution of services. For example, mapping the residences of parolees and probationers can help agencies optimize caseloads and improve the process of referring ex-offenders to nearby treatment facilities. In addition, novel data can provide new measures of concepts that are commonly used in geographic research, raise interesting research questions, and possibly introduce new avenues of research.
A third potentially fruitful area of research would involve increased attention to the differences between types of city features and the production of criminal events. As previously discussed, it is well established that certain city features tend to concentrate criminal events in adjacent areas. What remains to be seen, however, is how other spatial and community features contribute to differential spatial patterns of crime. For example, it is not entirely clear why some bars suffer from high levels of crime problems and others do not. Obviously, design features of the location itself should account for some of the differences, but other features, such as the level of community organization, adjacent land usage, and the level of concentration of other crime generators or attractors, may also be important for differentiating between problematic and nonproblematic bars.
A final recommendation for future research on spatial patterns in crime is to further examine the stability of crime in small areas. Specifically, as Weisburd, Bushway, Lum, and Yang (2004) recognized, few studies have examined the degree to which crime in microlevel areas is stable over time. In their study, conducted in Seattle over a 14-year period, Weisburd et al. found that there was a substantial amount of stability in the level of crime on street segments. Despite the high degree of stability in many places, some street segments exhibited either downward or upward crime trajectories. Obviously, additional research is needed to determine whether this pattern holds generally or is specific to the city of Seattle. This type of research will be very helpful in describing the factors that lead to the development, maintenance, and decline of crime in problematic areas.
The purpose of this chapter was to review some of the current research on crime mapping, the process through which crime analysts and researchers use location information about crime to detect spatial patterns in criminal activity. Although the history of crime mapping can be traced to the beginnings of the field of criminology, it is only recently that researchers and crime analysts have been able to engage in extensive mapping efforts, primarily due to the development of the desktop computer and GIS software. The emergence of the problem-oriented policing model, along with advances in the theory of criminal events, created a niche for crime mapping in police agencies. The popularization of computerized crime mapping through the Compstat program in New York led to a period of rapid adoption of crime mapping that continues today.
Several theories that are widely used in crime mapping research were also discussed in this chapter. Social disorganization theory argues that structural factors can compromise the social networks needed for social integration, which in turn reduces the capacity of communities to regulate the behavior of its members. Routine activities theory states that crime can be understood through the convergence in time and space of suitable targets, motivated offenders, and the absence of capable guardians. Defensible space and CPTED focuses on how the design of a physical space can prevent crime through increasing territorial functioning and enhancing surveillance capabilities. The rational choice and crime pattern theories of crime focus primarily on explaining how patterns of offender routine activities and target-searching strategies can increase the level of crime in particular areas. Taken together, these theories provide the conceptual backdrop for understanding the spatial distribution of crime and designing strategies to combat crime in high-crime areas.
Finally, this chapter aimed to elaborate on some of the major findings in crime mapping and spatial crime research, with particular attention to designing strategies to combat crime problems. It was argued that the best strategy for eliminating crime hot spots requires consideration of causal factors operating at both the neighborhood and site levels. This chapter concluded with a number of suggestions for future researchers examining spatial crime patterns through crime mapping. In particular, crime mapping research may benefit from efforts at theoretical integration, using crime mapping with additional agencies, further examining the source of differences in the production of criminal opportunities between city features, and examining the stability of crime areas over time.