Crime and terrorism in the 21st century call for advancement in the modeling and simulation of criminal events in the complex environment. This presentation reviews the field of computational criminology, an emerging blend of criminology, computer science and applied mathematics. Modern concerns about public safety and security include a focus on a range of events from less serious everyday crimes like shoplifting through to personal violent crimes like homicide and ultimately to terrorism. Underlying all of these events is a decision process or chain of steps in target identification, steps that focus first on rough and vague decisions and move towards the precise. Minor and major crimes involve people moving about in a known space in identifiable patterns to find weaknesses.