In MO 2.0, there used to be a police station allowing you to get police units. Even if campaign only it would be cool.
IMO police units were a game ruiner, thanks god they were removed. I mean, seriously, they took away every piece of realism, and seriousness from the game. Police car in the middle of a friggin battlefield, ffs.
A SWAT team in an urban campaign map wouldn't be too farfetched