Another trailer has been released for director Kathryn Bigelow’s new movie “Detroit,” which was shot in and around Boston last year. The film, starring “Straight Outta Compton” actor Jason Mitchell, John Boyega, Anthony Mackie, Will Poulter, Ben O’Toole, and John Krasinski, is about the riots that roiled Detroit in 1967. Judging from the trailer -- and a companion clip that includes commentary from Bigelow and a few of the people who lived through the riots -- the film focuses on an incident at the Algiers Motel, where three black men were killed and nine other people were beaten by members of the Detroit Police Department, the Michigan State Police, and the Michigan Army National Guard. Bigelow, who won an Academy Award for “The Hurt Locker,” worked from a screenplay by Mark Boal, who also earned an Oscar for “The Hurt Locker” script. “Detroit” comes out Aug. 4.