Presented from the viewpoint of a practitioner, this article discussed the chronology of events and issues addressed by the Jefferson Parish, Louisiana Sheriff's Office in successfully developing and implementing a comprehensive law enforcement GIS application for the benefit of both the department and the community. An effective design is a critical element in the successful implementation of a GIS application. The geographic infrastructure is an illustration of the community or service area. Several important issues are addressed when designing a GIS application: the depth of the application, its purpose, employee training requirements, and desired reports and maps. Once fully developed, the GIS application can have multiple uses within a law enforcement agency, such as area and neighborhood analysis, problem solving, and predictive modeling. In reality, the GIS is the graphic illustration of data elements and must be viewed as a data management application. When an agency deploys a GIS application, significant consideration must be given to user access. The implementation of a GIS application is neither inexpensive nor something that can be accomplished on a short-order basis. The most important lesson learned was that the development and implementation of an agency wide GIS application was an iterative process, a process of change and refinement. The GIS is an application customized to meet the agency's needs and operating routines. In addition to the above, other lessons learned and important to the implementation process included: iterative process, keep it simple, pre-formatted maps and reports, direct link to records management system (RMS), distribution, Web interface, current data, and training and user support. Several benefits were attributed to the development of a GIS application and included: (1) attain a geographical perspective of incidents and people within the community; (2) establishes credibility within the community; and (3) the visual perspective of data helps law enforcement officers understand what is happening in a community and spot trends which aids in providing remedial or corrective measures.