In the wake of national protests against police violence, Massachusetts established a civilian-led certification regime to institutionalize external oversight of law enforcement. This study evaluates the short-term behavioral effects of that reform on officers with documented histories of misconduct. Leveraging the alphabetically phased rollout of recertification, we use a natural experiment and difference-in-differences design to estimate the causal impact of POST participation. While our quantitative analysis does not reveal sweeping changes in the frequency of officer misconduct, it uncovers suggestive evidence of behavioral recalibration: officers appear less likely to engage in misconduct at all following exposure to external review. To contextualize these findings, we draw on semi-structured interviews with officers, supervisors, and oversight officials. These interviews reveal how officers often reject the legitimacy of POST while simultaneously adjusting behavior in response to reputational risk and the threat of sanction. Taken together, the results suggest that externally adjudicated, procedurally binding reforms can induce modest, short-term behavioral change through instrumental compliance.
Lanigan et al. (Sun,) studied this question.