"Gangster Squad" chronicles a bloody 1940s battle between Los Angeles police and mobsters. It culminates in a scene where gangsters shoot automatic weapons into a crowded movie theater from behind the screen.
The film is expected to be reshot and edited. A spokesman for Warner Bros. declined to comment on how the film would be altered.
"Gangster Squad" had been planned for a Sept. 7 release. The postponement means "Gangster Squad" won't be eligible for Academy Awards consideration this year, shifting from a plum fall release to a month often considered a dumping ground.
It's a blow for an anticipated movie with a starry cast. Directed by Ruben Fleischer, it stars Sean Penn, Ryan Gosling, Emma Stone and Josh Brolin.
The trailer for the film, which included footage from the movie theater scene, was pulled from theaters and the Internet after the Colorado shooting at a screening of "The Dark Knight Rises."
Shot at the famous Grauman's Chinese Theater in Los Angeles, the scene is a centerpiece to the film, meaning reshoots may be extensive.
Though the "Gangster Squad" trailer had been paired with "The Dark Knight Rises" (also a Warner release), it didn't play in the Aurora theater where a gunman killed 12 people last week.
This is the second time this year a high-profile studio movie has had its release altered by news events.
Twentieth Century Fox's "The Watch," which is out Friday, had its title changed from "Neighborhood Watch" after the Trayvon Martin killing in Florida. The film's trailer and promotional materials were also adjusted to distance the film from the incident.