PASADENA DOCTOR ASKS CLEMENCY FOR SLAYERA Pasadena doctor yesterday asked Gov. Knight for execu clemency for Billy Rupp, the 21-year-old killer of babvi Ruby Ann Payne who is scheduled to be executed Friday.' J‘l am the prison doctor who examined Billy Rupp when he entered San Quentin’s death row, Dr. William F. Graves,1 473 Kensington Place, wrote!c Knight. “In my view, Billy* Rupp does not have the mental v development nf the average 7-yen r-nkl child.andidafe Hits ance Chargeo“My plea. Gnvcriier. isthat you exercise f ily wisely givenuithor-(o modit\ ify a penalty which Is inappropriate* even i h o u g li lt;I technically correct/'Hupp, convicted of the slay-j; jing which occurred Aug. S.ic 1952. has been a death row! occupant since Dec. 10. 1fio2.!v Four previous execution dales!* been canceled. The U.S. Court turned down e last appeal on Nov. 5. 1956. is a former mental patient Camarillo State Hospital.