GIS and Evidence-Based Policy Making - Chapter 6 potx

6 Crime Map Analyst: A GIS to Support Local-Area Crime Reduction Paul Brindley, Max Craglia, Robert P Haining, and Young-Hoon Kim CONTENTS 6.1 Introduction 113 6.2 Current Crime Pattern Analysis 115 6.2.1 GIS Crime Systems in the United States 115 6.2.2 Past Crime Mapping and Analysis Research 115 6.2.3 Background to Crime Map Analyst 118 6.3 Overview of Crime Map Analyst 118 6.3.1 Density Maps 119 6.3.2 Repeat Victimization Identification 121 6.3.3 Temporal Analysis 122 6.3.4 Area Profiles 124 6.3.5 Origin=Destination Analysis 125 6.3.6 Ancillary Tools 126 6.4 Conclusions 127 Acknowledgments 129 References 129 6.1 Introduction The importance of geographical information systems (GIS) for crime analysis, and strategic and tactical deployment of forces, has been increasingly recognized in both the United States and the United Kingdom This was forcefully endorsed by former New York mayor, Rudolph Giuliani, during his visit to London in February 2002 ß 2007 by Taylor & Francis Group, LLC Senior police officers are keen to learn from the New York experience while Mr Giuliani visits London In the eight years he was mayor of New York crime plunged The success was credited to CompStat, the computerised system which keeps track of week-by-week crime figures for each precinct, the basic division of the city’s police department (The Guardian, 14th February 2002) CompStat is of course only part of a wider strategy of crime reduction, but it makes the point that the regular analysis of crime for small geographical areas is crucial for the effective deployment of resources, monitoring and evaluating impacts, and sharing intelligence The increased emphasis by the Home Secretary on increasing detection rates by concentrating police resources into selected hot spot areas goes in the same direction The ability to visualize and analyze the data geographically is at the heart of GIS These types of systems are already widely used in the United Kingdom, but there are significant variations among the forces in extent and purpose of use (Weir and Bangs, 2007) There are therefore opportunities for using GIS more and better, with stronger integration to crimereduction strategies both in the forces themselves and as part of the wider crime-and-disorder partnerships GIS can add value to the data already held by police forces and become a more integrated tool in crime-reduction strategies There are two essential preconditions to make this happen Geo-coded data GIS can only operate effectively if the data to be analyzed have accurate and consistent geographical locations attached to it Although this may sound a purely technical matter, it is in fact a largely organizational one It must become a routine to report the location of crime events as accurately as possible, and against a standard gazetteer of locations Not all forces have adopted such practice and the assigning of coordinates to past crime data provides context to the analysis Awareness and training Training staff in the use of GIS, or any new system, is of course time consuming and expensive The advantage however of adopting off-the-shelf and widely used software is that there are already well-developed courses, training packages, and learning resources, and that there is a support network of millions of users on which to build This minimizes training costs and makes the most effective use of the investment made Perhaps, more crucial is ensuring that the necessary awareness exists among senior managers of the value of such investment, and that adequate support is provided ß 2007 by Taylor & Francis Group, LLC 6.2 6.2.1 Current Crime Pattern Analysis GIS Crime Systems in the United States The importance given in the United States to GIS for crime analysis is most clearly demonstrated by the work of the Mapping & Analysis for Public Safety (MAPS) program (formerly the Crime Mapping Research Center) at the National Institute of Justice (http:= www.ojp.usdoj.gov=nij=maps) This = center was established in 1997 to promote, research, evaluate, develop, and disseminate GIS technology and the spatial analysis of crime The lessons learned out of the U.S situation are valuable in the continued development of crime mapping in the United Kingdom Personal contact using the CRIMEMAP e-mailing group (crimemap@lists aspensys.com) was undertaken to disseminate crime mapping and analysis e-mails to all subscribers to discover the main GIS used within U.S crime mapping The survey was conducted during 11–31 October 2000, and a total of 93 contacts were collected Findings support other crime-mapping surveys by several governmental crime-research agencies (Crime Mapping Research Center, 1999; Police Foundation Crime Mapping Laboratory, 2000), whereby over 50% of crime analysis and mapping in the United States was undertaken using just two software applications—ArcView and MapInfo 6.2.2 Past Crime Mapping and Analysis Research Since the 1990s, the extensive usage of GIS has enabled police forces to map and analyze crime data efficiently, facilitating crime data analysis (Hirschfield et al., 1995) Computerized mapping technology has broad application areas in various police fields including operational, analytical, and strategic policing (Craglia et al., 2000) GIS functionality has become widely used in many areas within crime data analysis, such as crime hot spot mapping and cluster detection, repeat victimization, temporal pattern analysis of crime incidents, and police policy making for crime reduction and prevention For hot spot analysis, Ratcliffe and McCullagh (1999) developed a methodology for detecting various hot spots using a kernel estimate function on the basis of a local spatial autocorrelation statistic (Local Indicators of Spatial Association, LISA) to identify statistical hot spot variation Crime cluster detection has been carried out within several current crime mapping tools such as STAC and CrimeStat (Bowers and Hirschfield, 1999; Levine, 1999; Craglia et al., 2000) Farrell and Pease (1993) recognized the issue of repeat victimization as a main criminological problem and suggested an implementation strategy for preventing crime repeats Anderson et al (1995) also provided strategic guidance for police forces to tackle repeat victimization Johnson et al (1997) demonstrated the relationship between repeat victimization ß 2007 by Taylor & Francis Group, LLC and other socioeconomic factors, and explored analytical methods to identify the relationship However, geo-coding problems have a profound impact upon the reliability of spatial repeat victimization identification (Ratcliffe and McCullagh, 1998a) The temporal aspect has been identified as a crucial factor to monitor crime incident change Instead of using general discrete methods (for example, using mid-point of between from-time and to-time interval), Ratcliffe and McCullagh (1998b) introduced a probabilistic rate technique based on aoristic rules to estimate a truer rate of crime incidents A fuller description of this methodology will be discussed in Section 6.3.3 Practical use of this method was undertaken to explore different temporal patterns of crimes within a number of hotpots (Ratcliffe, 2002) Spatial statistics have been increasingly applied to crime data analysis in order to enhance novel capabilities of GIS-based analysis of crime, such as local spatial statistics for crime pattern analysis (Craglia et al., 2000), urban crime examination (Murray et al., 2001), or detecting temporal changes of crime (Rogerson and Sun, 2001) Anselin et al (2000) introduced the extensive discussion of spatial analytical techniques and potential of GIS for crime analysis In addition, for exploring the relationship with socioeconomic area profile and crime incidents, Bowers and Hirschfield (1999) demonstrated an example of GIS applications in crime pattern analysis, and Craglia et al (2001) reported the strengths of GIS-based spatial analysis with census data for modeling high-intensity urban crime areas Hirschfield and Bowers (2001) summarized extensive research contributions of GIS and their practical potential in crime data mapping and analysis A variety of crime mapping systems, extensions, and software packages for GIS have been developed at practical levels, as summarized in Table 6.1 Some packages were developed for pinpointing crime events and creating thematic choropleth maps, whereas other software systems were developed for locating hot spots and exploring spatial relationship with other socioeconomic data For example, STAC was a frontier standalone hot spot and cluster analysis package developed in the 1980s and still is useful for crime cluster analysis (Craglia et al., 2000) In the 1990s, many mapping packages have been developed as extensions of main GIS commercial software systems using their customization languages such as SCAS, CrimeView and Crime Analysis for ArcView, and Hotspot Detective for MapInfo To improve their user interface, computer languages and scripts have been integrated such as Visual Basic (SCAS, RCAGIS, and CrimeStat), and MapObject (RCAGIS and Community Policing Beating Book, and MaxResponder) As an alternative, crimeoriented stand-alone mapping software has been developed such as PROphecy and CrimeWatch However, there has been limited success to tackle crime data analysis for various levels of U.K police force requirements Therefore, this chapter demonstrates some of the key functions of GIS crime analysis that can meet various operational, tactic, and strategic police performance in the U.K police force ß 2007 by Taylor & Francis Group, LLC TABLE 6.1 Summary of Main Available Crime Mapping Desktop Software Name Source Spatial Crime Analysis System (SCAS) Illinois Criminal Justices, 1993 (http:= = www.icjia.state.il.us=public=index cfm?metaSection ¼ Data&meta Page ¼ STACfacts, assessed 18th October 2007) CMRC, 1994 (http:= =www.usdoj gov=criminal, assessed 18th October 2007) Regional Crime Analysis GIS (RCAGIS) CMRC, 1994 (http:= =www.usdoj gov=criminal, assessed 18th October 2007) Community Policing Beating Book ESRI, 1997 (http:= =www.esri com=industries= lawenforce=beatbook.html, accessed on 6th June, 2002) ESRI, 1999 (http:= =www.esri com=industries=lawenforce= crime_analysis.html, accessed on 6th June, 2002) OMEGA, 1999 (http:= =www theomegagroup.com=crimeview htm, accessed on 6th June, 2002) ESRI, 1999 (http:= =www maxresponder.com=, accessed on 6th June 2002) Ratcliffe, 1999 (http:= =athene.csu.edu au=jratclif=index.html, accessed on 6th June, 2002) Ratcliffe, 1999 (http:= =athene.csu.edu au=jratclif=index.html, accessed on 6th June, 2002) Virginia Institute for Justice Information, 2000 (http:= =vijis.sys virginia.edu=home.htm, accessed on 6th June, 2002) Spatial Data Inc., 2000 (http:= =www spatial-data.com=pCrimeWatch htm, accessed on 6th June, 2002) Levine, 2000 (http:= =www.icpsr umich.edu=NACJD=crimestat html, accessed on 6th June, 2002) Spatial and Temporal Analysis of Crime (STAC) Crime Analysis Extension CrimeView MaxResponder Hot spot Detective Repeat Location Finder ReCAP-SDE CrimeWatch CrimeStat PROphecy ABM, 2000 (http:= =www.abm-uk com=uk=index.asp, accessed on 6th June, 2002) ß 2007 by Taylor & Francis Group, LLC Primary Functionality Hot spot analysis package Query interface; analytical mapping and reporting; installation flexibility; minimum reprogramming (avenue) Low cost (