Primary prevention focuses on current harmful influences in the community, the environmental forces which support persons in resisting them, and environmental forces which influence the resistance of the population to future pathogenic experiences. The police are especially relevant in this dimension of prevention, because they offer official authority and are frequently the sole official agency available to initial crises. Further, police should be involved in environmental impact assessment studies and assist in predicting the impact of new urban projects on the need for force services. The internal dimension of primary prevention focuses on ways to reduce the onset of new cases of destructive stress within the police organization and improve the quality of personal performance. The aim of secondary prevention is to reduce the disability rate due to disorder by lowering the prevalence of disorder in the community. The police are in a position to serve as early diagnosticians, referral agents, and even short-term crisis interventionists. The internal dimension of secondary prevention focuses on early detection of destructive stress within the police organization. The objective of tertiary prevention is to reduce the rate of defective functioning due to mental disorder. If police are to be effective in this dimension, they must prepare themselves to perform for the ultimate good of the offender as well as the community. The internal dimension of tertiary prevention focuses on returning a dysfunctional police officer to satisfactory performance as soon as possible. A total of 32 footnotes are listed.