As used in this section and ORS 237.620:
(1) “Firefighter” means:
(a) Persons employed by a city, county or district whose duties involve firefighting, but does not include volunteer firefighters; and
(b) The State Fire Marshal and the chief deputy fire marshal and deputy state fire marshals appointed under ORS 476.040.
(2)(a) “Police officer” includes:
(A) Police chiefs and police officers of a city who are classified as police officers by the council or other governing body of the city;
(B) Sheriffs and those deputy sheriffs whose duties, as classified by the county governing body, are the regular duties of police officers;
(C) County adult parole and probation officers, as defined in ORS 181A.355, who are classified by the county governing body for purposes of this section and ORS 237.620;
(D) Corrections officers as defined in ORS 181A.355;
(E) Employees of districts whose duties, as classified by the governing body of the district, are the regular duties of police officers; and
(F) Investigators of the Criminal Justice Division of the Department of Justice.
(b) “Police officer” does not include volunteer or reserve police officers or persons considered by the respective governing bodies to be civil deputies or clerical personnel.
(3) “Public employer” means any city, county or district that employs police officers or firefighters.