Except when they hire security contractors, and then that 3rd party assumes government powers - including police immunity - without the oversight. Which is what happens when cities ban technology uses such as facial recognition by the police - they just hire a 3rd party to do it with zero oversight. Same with large tourist events in non-tourist cities: those are not regular cops during the event, they are contractors with temporary police immunity and very little official oversight.
Except when they hire security contractors, and then that 3rd party assumes government powers - including police immunity - without the oversight. Which is what happens when cities ban technology uses such as facial recognition by the police - they just hire a 3rd party to do it with zero oversight. Same with large tourist events in non-tourist cities: those are not regular cops during the event, they are contractors with temporary police immunity and very little official oversight.