AN ASSISTANT DIRECTOR unwittingly handed Alec Baldwin a loaded weapon and told him it was safe to use in the moments before the actor fatally shot a cinematographer, according to court documents.

“Cold gun”, the assistant director announced, according to a search warrant filed in a Santa Fe, Arizona court.

Instead, the gun was loaded with live rounds and when Baldwin pulled the trigger on the set of a Western he killed cinematographer Halyna Hutchins.

Director Joel Souza, who was standing behind her, was wounded, the records said.

The Santa Fe County Sheriff’s Office obtained the warrant so investigators could document the scene at the ranch outside Santa Fe where the shooting took place.

They sought Baldwin’s blood-stained costume for the film Rust as evidence, as well as the weapon that was fired, other prop guns and ammunition, and any footage that might exist.

The gun was one of three that the film’s armourer, Hannah Gutierrez, had set on a cart outside the wooden structure where a scene was being acted, according to the records.

Assistant director Dave Halls grabbed the gun from the cart and brought it inside to Baldwin while unaware that it was loaded with live rounds, a detective wrote in the search warrant application.

It was unclear how many rounds were fired.