Toronto Video: Errol Morris on 'The Unknown Known' TORONTO - In his latest feature, the veteran documentary filmmaker Errol Morris points his camera at Donald Rumsfeld. "The Unknown Known" is a film-length interview with Mr. Rumsfeld, a longtime official in Washington who served as defense secretary under the George W. Bush administration. By asking difficult questions, Mr. Morris tries to gain a better understanding of the man and the decisions he made throughout his career. Mr. Morris brought the film here after it premiered in Venice, and in this video, he discusses why he decided not to interview others for the film and instead focused solely on his subject.