Boone frequently portrays a corrupt policeman or other authority figure, such as Seven (as an FBI agent) and as corrupt Detective Flass in Batman Begins. He has performed in over 70 movies, including 2 Fast 2 Furious, Get Carter, The General's Daughter, The Thin Red Line, and Die Hard 2. He has made guest appearances on TV in Law & Order, Seinfeld, Curb Your Enthusiasm, and several other shows. He played a small role in Armageddon and in an episode of the HBO prison drama series Oz. In 1984 he acted in The Way It Is (1985) by Eric Mitchell, which included actors Steve Buscemi and Rockets Redglare. He has appeared in some of Buscemi's directorial work, including Trees Lounge and as "Evil" in Lonesome Jim. (Buscemi was also in Armageddon.)
Boone was a regular cast member on the TV drama series Sons of Anarchy, playing Bobby "Elvis" Munson. In an episode of the TV series Quantum Leap, he played a biker named Maddog, similar to his character many years later in Sons of Anarchy. In 2011, he played the role of Vincent Dooly's father in The Mother of Invention.
He has appeared in two Christopher Nolan films, Memento, as Burt, the front desk manager at the Discount Inn, and Batman Begins, as Detective Flass, James Gordon's crooked partner.