If it was within MA it was probably some whacker volunteer firefighter that was embarrassed that he lost and decided to play vigilante. I know alot of people like this, I was a volunteer firemen for 7 years!
The MA state police have a lot of goodies. I went to a State Police mock search and rescue with my department one year and they had several camaros, mustangs, etc. There are even some based near me in Leominster and Holden MA. They also have a Ford ranger with a cap that they clock speeds with and a Nissan 300Z for chase that I used to see on the pike once in a while. They would sit on the side of the Pike together, the Ranger clockin speed and the Z chasin them down.