Alec Baldwin was handed a loaded prop gun by an assistant director who indicated it was safe to use, moments before the actor fatally shot his crew member, according to court documents.
The assistant director yelled "cold gun" before handing him the firearm on the set of the Western film Rust, a search warrant filed in a Sante Fe court showed.
He did not know the weapon was loaded with live rounds.
Cinematographer Halyna Hutchins was shot in the chest, while director Joel Souza was wounded.
Investigators obtained the warrant on Friday to document the scene where the incident took place.
The weapon that was fired was taken as evidence, along with Baldwin's blood-stained costume for the film.
Investigators also seized prop guns and ammunition that were being used on the set.
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Earlier Baldwin said he was devasted by the incident, saying on Twitter: "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.
"I'm fully co-operating with the police investigation to address how this tragedy occurred and I am in touch with her husband, offering my support to him and his family.
"My heart is broken for her husband, their son, and all who knew and loved Halyna."