The US Secret Service is seeking a driver who killed one pedestrian and injured at least two others while fleeing a police traffic stop near the National Mall in Washington DC. The shocking incident occurred shortly before 1.30pm on Wednesday, when uniformed Secret Service agents attempted to pull over a vehicle near 17th Street NW and Constitution Avenue NW, an agency spokesman told DailyMail.com. Lt. Paul Mayhair of the Secret Service Uniformed Division said federal agents with the division tried to pull over the vehicle after spotting its expired registration. 'The suspect indicated that they would stop the vehicle, but...