Strengthening police oversight: The impacts of misconduct investigators on police officer behavior

We study how civilian complaint investigators affect officer behavior in Chicago. We exploit quasi‐random assignment of complaints to supervising investigators and use variation in whether supervisors tend to acquire sworn affidavits that substantiate the complaints. When the assigned investigator opens more investigations through obtaining affidavits, accused officers accumulate fewer complaints in the first three months of the investigation. We find that, prior to a scandal, assignment to high‐investigation supervisors causes officers to make more arrests. However, this reverses after the scandal. Our findings suggest that police watchdogs can improve officer behavior in ordinary oversight environments but may backfire in heightened oversight environments.