After arresting Braddock junior, Price puts him in the patrol car and backs it up to leave the accident scene. If you look closely, Price only mildly pulls on the gear shift, but it never goes down into reverse, it stays in the park position, but the car backs up anyway.
Rather than worry about calling in federal troops or deputizing men to help with his security problem concerning Braddock junior, Price could have and should have called in the state police for assistance.