Interactions between officers and individuals with mental illnesses are infrequent, but they can be challenging. They typically involve the commission of a minor or "nuisance" offense, but an interaction can escalate to become volatile and dangerous. These interactions often require significantly more officer time than other calls for services, and officers are required to have special training and skills for managing individuals with mental illnesses. The effective police management of such cases may depend on the availability of community mental health resources to which officers can refer those with mental illness whom they encounter. Such cases typically involve repeat contacts with the same individuals, who live in the community with unresolved mental health needs. Specialized training for effective law enforcement strategies in dealing with individuals with mental illness should be designed to improve officer safety in dealing with such cases; increase mentally ill persons' access to mental health treatment, supports, and services; and decrease the frequency of these individuals' encounters with the criminal justice system. Such specialized training can also reduce certain costs incurred by law enforcement agencies in dealing with mentally ill individuals. A research-based approach for dealing with these cases is important for the development and assessment of training, agency policy, and officer performance in the field. 53 notes, a 37-item bibliography, and appended discussion of apparent inconsistencies in relevant law enforcement research and a detailed list of research questions that should be addressed in future research