Patrick Sheane Duncan was the son of migrant fruit pickers. He had his first brush with show business as a boy in Los Angeles. As a shoe shine boy, one of his regulars, a movie theater manager, would pay with passes to current films playing. After his father was murdered, the family moved to Michigan.

He enlisted in the U.S. Army in 1965 to qualify for the G. I. Bill. While in the army, he spent 15 months in Vietnam, which formed a basis for some of his projects. Patrick returned to Michigan where he graduated from college in two years. Soon, he joined with a professor in Grand Rapids to open an art-house theater. Within a year, they had turned a profit and Duncan was hired by Goodrich Theatres as general manager. Not liking the quality of films he saw and challenged by his wife, he began writing scripts and decided to go to L. A.

Once there, He found employment with Roger Corman’s New World Pictures but as an accounts receivable clerk. Then he moved to Crown International as assistant controller but was given a chance as a screenwriter. The Beach Girls, 1982, an exploitative film. He then spent several years doing uncredited rewrites of Chuck Norris films. In the early 80’s, he was invited to participate in a workshop at Sundance Institute. He developed "84 Charlie MoPic" (1989) which premise was a cameraman following a reconnaissance mission shot with hand-held cameras and played a cast of newcomers. It earned respectable reviews. It led to HBO to write and produce some episodes of "Vietnam War Story" and then a series of syndicated movies, "Medal of Honor: True Stories of America’s Greatest War" (1990-1).

Other films include: "A Home of Our Own", which won critical acclaim, "The Pornographer" which played in Sundance but was not widely distributed. With John Badham’s "Nick of Time" with Johnny Depp, and Stephen Herek’s "Mr. Holland’s Opus" starring Richard Dreyfuss and "Courage Under Fire" with Denzel Washington, it his reputation was set.