Despite increased recent attention to improving the quality of encounters between police officers and people with serious mental illness, there are no measures available for assessing how consumers perceive their interactions with police officers. Drawing upon conceptual frameworks developed within social psychology, this study reports the development and testing of a new measure, the Police Contact Experience Scale (PCES), which yields indicators of procedural justice and coercion as evaluated by persons with mental illness in relation to specific encounters with the police. The PCES was administered to 154 individuals with mental illness that had police contact within the prior 12 months. Rasch rating scale analysis supported construct validity of a 10-item procedural justice and a 5-item coercion scale. Correlational analysis supported convergent validity for both scales. (Contains 4 tables and 2 figures.)