Story highlights "Gangster Squad" has been postponed

The trailer was pulled from "The Dark Knight Rises" screenings because it featured a theater massacre

Warner Bros. declined to comment on the decision

The July 20 shooting spree at a midnight screening of "The Dark Knight Rises" in Aurora, Colorado, seems ultimately to have had a relatively modest impact on the release of the superhero blockbuster, at least in terms of its box-office performance

But it has thrown a major wrench into Warner Bros.' plans for another film, the upcoming action-drama "Gangster Squad." In the immediate wake of the shooting, the studio pulled the trailers for the film , which — in a grisly unintended echo of the Aurora tragedy — featured a scene of mobsters bursting through a movie screen and firing machine guns at people seated in a movie theater.

Days later, the studio and director Ruben Fleischer ("Zombieland") decided to cut, or at least extensively rework , that scene. Given that the movie-theater-gangland-massacre sequence was a key plot point in the film — which stars Josh Brolin and Ryan Gosling as Los Angeles cops assigned to take down real-life 1940s mob kingpin Mickey Cohen (Sean Penn) — any changes to it inevitably would necessitate script revisions and reshoots, jeopardizing the film's planned Sept. 7 release date.

Now a source confirms that Warner Bros. is pulling the film off of the fall schedule. No new date has been determined yet, though according to the Hollywood Reporter , the studio is eyeing dates in January as a possibility.

Warner Bros. declined to comment on the decision, but clearly moving the film will both allow the filmmakers the time required to make changes to the movie and give the studio an opportunity to reboot a marketing campaign that was derailed by horrible circumstances no one could have foreseen.