The author argues that in order to develop effective crime prevention responses, it is necessary to know the basic theoretical principles of human behavior and to formulate a clear statement of the problem. The chapter begins with a review of important theoretical concepts necessary in the development of situational responses to crime and disorder, including discussions of crime pattern theory, routine activity theory, rational choice theory, and the crime triangle. In this section the author also recommends that any crime prevention strategy should be informed by a consideration of the mechanisms through which the strategy will work – which is essentially the same thing as formulating a hypothesis. Next, several issues that should be considered in the process of crime response development are described and include the recommendation to “think thief,” use “crime scripts,” be alert for “crime chains,” consider iterative crime problem-solving techniques, and combine overlapping concepts from different theoretical perspectives. The author also suggests focusing on the motivating factors within offense sets, identifying problems at their outset, identifying crime facilitators, and attending to project implementation issues. In order to illustrate the importance of crime theories in the development of crime prevention strategies, the author offers a complex example of response development in practice. The fictitious example considers crime and disorder in a city center and addresses not only the theoretical underpinnings of the crime problem and its response, but also the mechanisms through which the response might work. In closing the author notes that central governments can approach crime and disorder prevention not only from the perspective discussed here, but can also prevent crime by considering the potential consequences of new technologies and public policies. Whatever perspective taken, it is important that the overall approach to crime and disorder be scientific and research driven. Figure, tables, note, references