St. Louis County police have apologized for a white officer’s reference to the “headless horseman” while questioning a black family Friday about what they were doing at a home in the Mehlville area. Dale C. Watson, 47, of St. Louis, said in an interview Tuesday that while he appreciates the apology, he wants the police department to discipline the officer and take steps to prevent similar behavior by its officers. Watson said he, his wife, his nephew and his niece were fixing up a foreclosed home on Shady Green Drive for a real estate firm Friday morning when two St....