Alec Baldwin shot and killed cinematographer Halyna Hutchins, 42, on set of the Western indie Rust on Thursday.
The Santa Fe County Sheriff’s Office is investigating the shooting, which occurred during the filming of a scene.
A source says there were two misfires on the prop gun and one the previous week.
The film’s camera crew walked off the set in protest of their working conditions before the accident, according to reports.
Actor Jensen Ackles, who stars in the film alongside Baldwin, addressed gun preparation on set just days before the tragedy last weekend.