Most GIS systems process huge amounts of data but lack the capability to produce useful knowledge and actionable information. Unless GIS information generates a Bayesian update (a surprise or information that decision makers cannot anticipate), this GIS remains weak and a simple storage of dead data. Furthermore, even if this GIS stores valuable data, it still remains weak if it lacks the ability to generate the decision support that users need. This work in progress aims at adding decision support capabilities to a standard law enforcement GIS in terms of two main features: 1) visual decision support at the functional management and control levels in remote locations of police stations protecting their urban zones, and 2) evidence-based decision support at the strategic management level in the police department protecting the conurbation constituting the urban zones under its jurisdiction. The visual decision aids employ dynamic choropleth maps that are revised on a monthly basis. The evidence-based decision process is provided using Dempster and Shafer theory. While some of the tools are primarily used by police departments to devise effective policing strategies, police chiefs supervising the police stations can also locally benefit from adopting them. This study provides a numerical example to demonstrate the working of the proposed decision aids.