Warner Bros. is in talks to cast Holt McCallany (”Lights Out”) in period drama ”The Gangster Squad.”He’ll portray a bodyguard for Mickey Cohen, who’s being played by Sean Penn. Production starts Sept. 7. Kevin McCormick and Dan Lin are producing with Ruben Fleischer helming from Will Beall’s script. Jon Silk, of Lin Pictures, is co-producing. Project is based on the Los Angeles Times’ seven-part series “Tales From the Gangster Squad,” which Warner acquired the rights two years ago. The articles, penned by Paul Lieberman, chronicled the LAPD’s struggle with increasing crime and corruption in the 1940s by forming the Gangster Squad to keep East Coast organized crime figures out of Los Angeles. Ryan Gosling, Josh Brolin, Anthony Mackie, Michael Pena and Giovanni Ribisi also star.