Crime Mapping: New Tools for Law Enforcement.
Geographic information systems (GIS), commonly referred to as crime mapping, are becoming indispensable crime-control tools for law enforcement executives. With the advent of inexpensive desktop computers and user-friendly mapping software, employing crime maps as a way to evaluate intelligence data, develop strategies, deploy personnel, and monitor crime trends is crucial for effective law enforcement.
Authors Irvin B. Vann and G. David Garson have written a comprehensive, easy-to-read guide on crime-mapping essentials. They make several salient points about the effectiveness of crime mapping and the ease with which agencies can prepare crime maps. The first two chapters introduce crime-mapping basics, common terminology, and the varieties of crime maps. The authors succinctly explain how to build spatial databases and interpret data output. Chapter 3 details how to manage crime with GIS through specific types of maps. Some of the examples include displaying drug-free school zones by creating 1,000-foot buffer zones, integrating problem-oriented and community policing, and allocating resources.
Chapter 4 explains spatial models that concentrate on specific situations, such as the relationship between convenience store robberies and actual store locations. Another example involves displaying burglary locations to known burglars' residences. This type of modeling is imperative to situational crime prevention. The authors also describe multivariate analysis, which constitutes the most compelling part of the book. Because crime often is linked to environmental and demographic conditions, building a multivariate model allows crime analysts to examine the relationship between specific crimes (e.g., auto theft, homicide, robbery, and burglary) and social, demographic, or environmental conditions (e.g., poverty, unemployment, the elderly, young adults 16 to 24, abandoned houses, and vacant lots). Multivariate analysis represents the key to designing successful situational crime prevention programs because a solution depends on a thorough analysis of the precursors to the problem.
Chapters 5 and 6 discuss how crime mapping influences decision making. This includes a review of the SARA (Scanning, Analysis, Response, and Assessment) model of problem solving and New York City's Compstat and Philadelphia's Crimestat processes, which serve as two outstanding examples of how crime mapping represents one part of a larger crime-control process. The book concludes with a discussion about social policy and how crime maps may have unintended consequences, such as the right to privacy because many police departments upload their maps to the Internet for community use.
The book is replete with actual experiences from various law enforcement organizations throughout the country, including large and small departments, municipal and county police agencies, and sheriff's offices. It offers an excellent reference section for additional reading and an appendix of law enforcement Web sites with crime maps. The book is an excellent supplement to any academy text or management course on crime-control strategies, community policing, situational crime prevention, and problem solving.
Captain Jon M. Shane
Newark, New Jersey, Police Department