He was a writer for the first two Dirty Harry films, received an Academy Award nomination as screenwriter of Apocalypse Now, and wrote and directed The Wind and the Lion, Conan the Barbarian and Red Dawn.
Foi un dos guionistas dos dous primeiros filmes da saga Harry o sucio. Recibiu un nomeamento ós Oscar como guionista de Apocalypse Now, e escribiu e dirixiu O vento e o león, Conan o bárbaro e Red Dawn.