The geographic profiling problem is to create an operationally useful estimate of the location of the home base of a serial criminal from the known locations of the offense sites. We have developed and released new software based on Bayesian methods that attempts to solve this problem. In this paper, we discuss some of the geographic and computational challenges in implementing this new method. Categories and Subject Descriptors J.4 [Computer Applications]: Social and Behavioral Science--sociology; G.3 [Mathematics of Computing]: Probability and Statistics--statistical computing; I.6 [Computing Methodologies]: Simulation and Modeling--applications General Terms Algorithms Keywords Criminology, geographic profiling