Police patrol officers learn, harbor, and utilize preconceptions or stereotypes daily. This study focuses on the importance of this process in the context of police response to the domestic disturbance call because this type of call will bring out the maximum degree of discretion exercised by the officer. In addition, the domestic disturbance call is one context in which to gain a further understanding of the justice system's management of private and family violence. Data were obtained through the use of interviews and participant observation of a small municipal police department on the West Coast which employs 61 sworn officers. Officers were observed and interviewed across all shifts for 6 months. Findings revealed that officers harbor a fairly complex pattern of preconceptions about domestic disturbance calls. They tended to categorize citizens involved not in terms of their abstract traits, such as age or ethnicity, but rather in terms of the practical implications of the citizens' perceived character. Officers categorized the citizens in the domestic disturbance situation in terms of the stability of the citizen as a grievant and the reliability of the citizen as a complainant. Further, officers tended to stereotype the domestic disturbance call as not likely to lead to arrest. The relationship between the domestic disturbance call and police handling of the call requires further study. Eleven footnotes and 38 references are provided.