Police internal affairs units: results from a national survey

PurposeThis study aims to obtain information regarding the personnel, policies and practices of Internal Affairs (IA) units in large, municipal, US police departments.Design/methodology/approachThe authors administered an 85-question survey to 436 departments that employed 100 or more full-time sworn officers in 2019 to inquire about their IA units, and 198 (45.4%) responded.FindingsThe authors find considerable variation in terms of the organization and management of IA units, frame policy findings in terms of IA’s best practices specified by the Office of Community Oriented Policing Services and find variation in adherence to these practices as well; some policies and practices are almost universally adopted, while others are much less frequently followed or even go against best practices.Originality/valueThere has only been a single study conducted of IA units and that is over three decades old. This study provides a much-needed expansion and update regarding the form and function of IA units in the US.