David V. Cox, 27, whose Marine court-martial was depicted in the Broadway hit play and film “A Few Good Men.” Cox and several other Marines were charged in the beating death of a fellow Marine. Seven accepted plea bargains, but Cox and two others chose court-martials. Cox was acquitted and later received an honorable discharge. His experiences formed the basis for the successful play and the recent film starring Jack Nicholson, Tom Cruise and Demi Moore. Cox had been reported missing by his girlfriend Jan. 4. Found shot to death on Saturday in Medfield, Mass.