Yes. I also have a responsibility nationally for leading on this area for the Association of Chief Police Officers in the U.K. I can tell you that the profile of complaints is handled predominantly within local police forces because overwhelmingly they are about things like rudeness, incivility, lateness, those sorts of service issues.
When matters are more serious, and these thankfully are fewer and farther between, we have an Independent Police Complaints Commission to which these more serious matters are referred, such as death following police contact or an allegation of corruption, those sorts of things. The Independent Police Complaints Commission can do one of two things: they can independently investigate that, and they would do this for very serious matters, or they could manage an investigation and oversee a police force investigating that locally.
Overwhelmingly, complaints need to be dealt with by local supervisors because very often it is just an officer getting something wrong that needs to be put right with a simple “sorry” and service recovery.