In 1979, the megahit Charlie's Angels was entering its 4th season and executive producers Aaron Spelling and Leonard Goldberg were looking for a replacement for exiting cast member Kate Jackson. An extensive search was made and many beautiful women (models and actresses) auditioned. Shelley Hack said, "I remember there was a big Angel hunt going on, and they asked me to audition. The hunt seemed to go on for a long time. A lot of my girlfriends went in to be tested, but I wasn't involved until sometime later when my agent called and said, 'It's a terrific show - you really should think about testing.' So, I thought about it again and went in." By then, Shelley was already a Supermodel and was familiar to the public as being THE Charlie Girl in those fabulous Charlie perfume print ads and commercials. By late May that year, Shelley was cast as Charlie's newest Angel Tiffany Welles. "THE Charlie Girl Becomes Charlie's Newest Angel" was a headline producer Aaron Spelling just couldn't resist.