Dodge Ram Van used by police department is a 1986-1993 model as denoted by two large rectangular headlamps. If it were a 1984 and earlier model, the headlamps would be a set of two large round headlamps (lower trim or fleet version) or a set of four smaller rectangular headlamps.
Some of Chevrolet Caprice police cruisers have tapered-shape external rear-view mirrors, which were introduced in 1986 model year and continued until 1991.