The King County prosecutor filed four felony charges of vehicular homicide and vehicular assault yesterday against Mark W. Mullan. He’s the alleged drunken driver who killed two people and wounded two others in the Wedgewood neighborhood in Seattle on Monday. The case has provoked scrutiny of the state’s approach to drunken driving. Ross Reynolds examines the history of drunken driving prevention efforts in the United States, digs into the ramifications for drunken driving in Washington and asks callers for their opinions on our state's DUI penalties.