On May 24, 2012, it was announced that Warner Bros. had acquired the rights to Kyle's book with Bradley Cooper set to produce. Cooper originally had Chris Pratt in mind to play Kyle but the studio agreed to buy it only if he would star. September 2012, director David O. Russell (Silver Linings Playbook (2012) and American Hustle (2013)) stated that he was interested in directing the film, but ultimately left the project. On May 2, 2013, it was announced that Steven Spielberg (Jaws (1975), War Horse (2011) and Lincoln (2012)) would direct. Spielberg had read Kyle's book, he was responsible for adding the psychological conflict in the film. His contribution led to the development of a lengthy screenwriting process, culminating in a 160 page script. Due to Warner Bros.' budget restraints, Spielberg felt he could not bring his vision of the story to the screen, and thus dropped out of directing. On August 21, 2013, it was reported that Clint Eastwood (Unforgiven (1992) and Million Dollar Baby (2004)) would instead direct the film. In the following early months in 2014, Sienna Miller, Kyle Gallner, Cory Hardrict, Navid Negahban, Eric Close, Eric Ladin, Rey Gallegos, Jake McDorman, Luke Grimes and Sam Jaeger. Kevin Lacz, a former Navy SEAL, was also cast and served as a technical advisor. As well as former Navy SEAL, Joel Lambert. Filming began in Los Angeles and Morocco in March 2013 and the rest is history.
The film stars Bradley Cooper as Chris Kyle and Sienna Miller as Taya Renae Kyle. The two leads gave powerful performances, especially Cooper. Who gave the best performance of his career, he conveyed a near-perfect embodiment of Kyle himself. He walked and talked like Kyle.