Jack Booted Thug ... has to do with a small minority of police officers that believe their roll in the community is to rough up and shake down anyone they perceive as undesirable.
Got some rust on your car, well that might put you in their cross hairs.
Small minority?
Oh, and it's "role."
A "roll" is something you bake and eat at dinner.
Why do so many adults have kindergarten-level writing skills these days?