Most of the 12 networks focus on the mentally ill. Each such network has a special 24-hour unit that screens persons, identifies an appropriate facility to which to refer them, and provides on-scene emergency assistance. The benefits of the networks for police are time savings, danger reduction, and increased job satisfaction. Mental health professionals benefit by spending less time evaluating, treating, or transferring inappropriate police referrals. Local government officials find that networking addresses the concerns of downtown merchants and the public about the mentally ill, public inebriates, and the homeless. In establishing and sustaining a network, all pertinent agencies should be involved in planning, and each agency should have a clear understanding of the special problems each facility will handle. Interagency agreements should be in writing, and each agency should monitor staff compliance. Program effects and successes should be monitored and documented. Ingredients for network success include appropriate training, effective communication, supportive legislation, and adequate funding. Appended additional case studies, local networking documents, and 18 references.