Most police agencies use computers and information systems for administrative purposes, but in recent years many have been using computers for analytic purposes as well. There has been an increase in recent research on complaints filed against police officers by citizens. Some agencies are now reviewing citizen complaints as part of their COMPSTAT-like process (processes that use computer comparison statistics). The aim of this study was to demonstrate how police agencies can use GIS to shift some of their focus to more internal matters such as complaint analysis, and take advantage of the inferential capabilities of the geography-based approach. The data consisted of all complaints filed against Philadelphia police officers between January 1998 and April 2000 within the 23 Philadelphia police districts. This included all complaints filed by civilians as well as complaints filed by Philadelphia police personnel. By far the most common type of complaint filed against a Philadelphia police officer during this time period concerned the officer’s actions while off duty, while the second and third most common concerned an officer abusing a civilian, either verbally or physically. Understanding why this is, whether it is due to a training issued, or perhaps an organizational culture issue, needs to be a goal of any responsible police department. The analysis suggests that the location of the complaint and the residence of the complainant can offer departments an additional method for understanding the complaints filed against officers. An examination of complaints data in conjunction with arrest data or calls for service data may provide the police department with other insights relevant to current and future problems within the separate districts. 12 figures, 1 table, 15 references