I was driving through PA not too long ago and spotted a white 1995 or 1996 Caprice. It had "Special Police" markings all over it (in blue stripes), an ALL BLUE light bar (no red at all) and a regular civilian license plate (not the white over blue municipal tag). The driver was not wearing any uniform at all.
Was this just a security car from a gated community or something like that? I don't live in PA, but I know that all "real" police cars are supposed to have both red and blue lights and they'll be sporting the 'municipal government' plate on the back. Firefighters usually have blue lights on their personal cars, so maybe this guy was 'fire police' or something like that.
Anyway, being from VA, seeing an "all blue" light bar made me look twice. Perhaps a "special police" officer in PA is just someone who has limited jurisdiction or arrest powers under certain circumstances......I don't know. Heck, maybe he was a constable or something.