1970 Dart police cars????????

Just a topic of interest and for discussion. Does anybody know what years the Darts were actually used for police cars? The reason I ask is when my friend looked at the build sheets on the 1970 Dart Custom I brought home a while back, he said it was supposed to be a police car. Now we looked the car over and there is no structural addition in the roof for the light bar, in fact there is nothing related on the car. Did Dodge have and then lose the contract in 1970? I've been thinking, (if I could ever get to it!) that it would be cool to build a real "one of none" someday and maybe this could be it. I have googled and can't find any pictures of a 1970 Dart in police attire. If there ever was and anybody has pics, I would like to see them.
I have a 1970 dart swinger 225 auto with
A38 police package. Funny it's a 2 door, maybe a detectives car or something. I see nothing extra special with the car, maybe I'll measure the torsion bars & count the springs out back. Did you find anything out ?