The 1974 Universal Studios annual report contained an advertisement for "Radioland Murders" as being in preparation. The ad gives the credits as "screenplay by Willard Huyck and Gloria Katz" "Produced by Gary Kurtz" and "Directed by George Lucas"
While prominently billed, George Burns is only in the film for a little over a minute. He also only had three scripted lines. The rest of his dialogue came from a previous performance in "An Evening With George Burns".
During a February 1995 appearance on "Howard Stern", Corbin Bernsen (Dexter Morris) admitted that this is the only film he's left the theater during the middle, and was persuaded to by his family who was also in attendance.
Penny's (Mary Stuart Masterson's) costume throughout the film, once she removes the jacket from the opening scenes, is a copy of the costume Katharine Hepburn wore in the final scene of Woman of the Year (1942), complete with falling shoulder straps on the jumper.