BOSTON — A state police troop currently under investigation for an alleged overtime scam has been previously assessed for contracting irregularities.The Boston Globe reports State Police Troop E pushed thousands of motorists to use Perfection Towing of Watertown when it favored the business with a three-year contract.Members of the Massachusetts Department of Transportation and three lieutenants from Troop E also allegedly rigged the system against Perfection Towing's competitors.