The Secret Service has put a senior supervisor on leave and suspended his security clearance after a female employee accused him of assaulting her after-hours at agency headquarters last week, the agency said Wednesday. The D.C. police’s sex-crimes unit and a government inspector general are investigating the female agent’s allegation that Xavier Morales, a manager in the security clearance division, made unwanted sexual advances and grabbed her on the night of March 31 after they returned to the office from a party at a downtown restaurant, according to two law enforcement officials with knowledge of the probe