A renewed approach to professionalising the police has produced new institutions and a shift towards professional ownership of research about policing. Research into policing has long been a contested area and the chapter explores how the new police professionalism may affect the process and ethics of police research. Operation Turning Point, a randomised controlled trial testing diversion against prosecution, is used as a case study to explore this through a discussion of the impact on research motivation, consent, risk and harm assessment and the researcher role.