Wallace has also written 25 romance novels, under her own name and the pseudonyms Pamela Simpson and Dianne King.
The original script for Witness was conceived by Pamela Wallace in the 1970s and was inspired by an episode of the western drama series Gunsmoke.
The idea was turned into a screenplay by her husband Earl W. Wallace and his colleague William Kelley in 1983.
The resulting film, Witness, was released in 1985 and starred Harrison Ford and Kelly McGillis.
[5] In the late 1980s Wallace collaborated with fellow screenwriter Madeline Dimaggio on a screenplay they called If The Shoe Fits.
Drawing on her own experiences in Hollywood, the book walked readers through the entire screenwriting process, beginning with the initial idea.