I’m surprised I’m the first to make this point:
To me, police are clearly “civilians” just like all the rest of us non-military folks, because they, like us are (at least in theory) subject to the “civil code”, as opposed to members of the military who are governed by the Uniform Code of Military Justice:
I quite prefer the word “citizen” as it seems to emphasize the fact that we have rights which ought to be respected by those enforcing our laws.