Purpose: The purpose of this paper is to conceptualize a stage model for maturity levels for police oversight agencies. Design/methodology/approach: The paper is based on a literature review covering police oversight organizations and stages of growth models. Findings: As a conceptual paper, the main findings are related to the appropriateness of the stage model, each identified stage, and the characteristics of each stage. Research limitations/implications: An empirical study of police oversight agencies all over the world would be necessary to verify the proposed stage model. Practical implications: The managers of police oversight agencies can apply the model in three ways: identify the current status; identify future direction; and evaluate the past progression. Originality/value: Hitherto, knowledge transfer from police misconduct cases has not been conceptualized as a learning process in police districts and general law enforcement. (Contains 1 table and 2 figures.)