John D.Gaul;of Fayette City R.D.1;police chief of Washington Twp.;was dead on arrival Friday;Sept.15;1978;at 8 p.m.in Charleroi Division of Mon Valley Hospital.  He was 46.  Mr.Gaul was born April 12;1932;in Monessen;a son of Lillian Brooks Gaul of Belle Vernon;who survives;and the late Norman Gaul.  He was employed at the Monessen Plant of Wheeling-Pittsburgh Steel Corp.and was a Protestant by faith.  A veteran of the Korean Conflict who served in the U.S.Army as a sergeant;Mr.Gaul was a member of Fairhope Veterans of Foreign Wars Post.   In addition to his mother;he is survived by his widow;Rochelle Palfi Gaul;and two sons;John Norman Gaul and Ricky Gaule;both of Belle Vernon.  He was preceded in death by his father;Norman Gaul.  Friends will be received in the Howard W.McCrory Funeral home;Fayette City;after 4 p.m.Saturday.  Services will be held in the funeral home Monday at 1:30 p.m.with the Rev.Frank D.Garlathy of the Fayette City United Methodist Church officiating.  Interment will be in Belle Vernon Cemetery.  The Howard W.McCrory Funeral Home is in charge of arrangements.