Wonder if that is one of the special Mercury Marauders that was done for a few of the local LE agencies.
IIRC, there was a guy originally from Southern Indiana that was making special addition highway patrol cars out of the Marauders down in Florida, and also did a few for some agencies up here.
There's a sign warning that you're on "camra" at a gas station in between Gary and East Chicrapo along Rt 12 full of spelling and grammatical errors that I keep meaning to take a picture of.