Investigating complaints against police misconduct is vital to accountability, and this task is commonly delegated to Internal Affairs (IA) units within large police departments. IA units vary considerably in the degree to which they find evidence of misconduct in their investigations, but there has been little exploration of this issue. Extant research suggests this variation could be attributable to either features of the citizen complaint process or to the quality or intensity of IA unit investigations, so we more closely examine this issue.
This paper uses data from a 2019 survey sent to the IA units of 436 large police departments, of which 128 responded and provided complaint dispositions. Fraction regression is employed to analyze those data.
Departments which provided specialized training to their IA officers upon appointment and those departments that engaged in collective bargaining sustained a lower proportion of complaints than those that did not. All other variables were not found to be significant and thus suggest that neither the majority of features of the citizen complaint system nor the quality of IA investigations affect the outcomes of citizen complaints.
While research has examined the proportion of sustained complaints before, no studies to date have been able to include citizen complaints or IA unit-specific features.
