Actor Alec Baldwin, who fatally shot a cinematographer on a movie set on Thursday, was given a prop gun by an assistant director who said it was “safe to use”, AP reported citing court records. The assistant director did not know it was loaded.

Cinematographer Halyna Hutchins was shot in the chest by Baldwin on Thursday while working on the movie Rust. The film’s director, Joel Suza, was injured.

The police obtained a warrant on Friday to document the scene at the ranch outside Santa Fe, where the movie shooting was taking place. Baldwin’s blood-stained costume, other prop guns, ammunition and footage of the scene were taken as evidence.

Juan Rios, a spokesman for the sheriff’s office, on Friday said that the police were on the movie set interviewing potential witnesses, The New York Times reported. “Regarding the projectile, a focus of the investigation is what type it was and how did it get there,” Rios said.

Meanwhile, the International Alliance of Theatrical Stage Employees said that the prop gun contained a “live single round”, according to Variety.

The film’s production company, Rust Movie Productions, said that it was conducting an “internal review” of it procedures and that the filming of the movie was shut down, Reuters reported.

On Friday, Baldwin – who is a producer on the film – said that that he was cooperating with the police in its investigation. No charges had been filed and the police were investigating the case.

“There are no words to convey my shock and sadness regarding the tragic accident that took the life of Halyna Hutchins, a wife, mother and deeply admired colleague of ours,” Baldwin had said in a tweet.