Trust in the police is key to the state’s legitimacy and social development. Despite its relevance, many countries still have significant challenges in generating such trust. This paper presents a conceptual framework and a survey instrument to measure public trust in the police and explore some potential determinants: procedural justice, perceived effectiveness, the convergence of values between citizens and the idea of police forces, and integrity. We piloted the instrument in five Colombian cities---which represent 15% of the population---to examine its validity, finding satisfactory results. The descriptive results suggest that public trust in the police is strongly associated with the perception of the application of fair procedures, the convergence of values, and, to a lesser extent, perceptions of the effectiveness and integrity of the police. We validate the relevance of procedural justice with a vignette experiment, which shows that fair treatment increases acceptance and satisfaction with police actions and fosters citizens’ willingness to collaborate with the police. This study provides a practical tool to measure public trust in the police and its possible determinants and thus guides public policy efforts to strengthen it.
