THE MAN WHO handed Alec Baldwin the gun that killed a cinematographer admitted he didn’t fully check it, documents revealed yesterday, as the sheriff investigating the fatal shooting spoke of “complacency” on the US movie set.

Halyna Hutchins died after Baldwin shot her with the Colt .45 he was pointing at a camera for low-budget western “Rust” being filmed in New Mexico.

The live round passed through her and struck director Joel Souza in the shoulder.

Assistant director Dave Halls told detectives he remembers seeing ammunition in the period weapon before he handed it to Baldwin. Filmmakers sometimes use inert, or dummy, bullets in props.

“He advised he should have checked all of them, but didn’t, and couldn’t recall if (armourer Hannah Gutierrez-Reed) spun the drum” to show him what was inside the gun,” an affidavit says.

Halls handed Baldwin the weapon using the phrase “cold gun” – an industry term for an inert weapon.

An investigation into last Thursday’s fatal shooting has recovered 500 rounds of ammunition from the set, Sheriff Adan Mendoza told reporters, adding that detectives believe they were a mix of blanks, dummies and live rounds.

Entertainment trade website The Wrap reported this week that crew members had been using prop weapons just hours before Hutchins was killed, shooting at tin cans for target practice.

“We have recovered what we believe to be possible additional live rounds on set,” Mendoza said.

“We’re going to determine how those got there, why they were there, because they shouldn’t have been there.

“I think there was some complacency on this set,” he added.

As the film’s armourer, Gutierrez-Reed would have been responsible for supplying and keeping weapons safe on set, ensuring that they are accounted for at all times and locked away when not in use.

She told detectives that on the day of the incident guns were secured while the crew ate lunch, but that ammunition was not, according to the affidavit.

Mendoza told reporters more questions were being asked of the people who “inspected or handled the firearm… before it got to Mr Baldwin”.

“We’re going to try to determine exactly how that happened and if they should have known that there was a live round in that firearm.”

Rust crew members had complained about lax on-set protocols, and a gun was mistakenly fired at least twice on set in the days before Hutchins’ death, multiple US outlets have reported.

It emerged this week that Halls had been sacked as assistant director of a previous production because of a gun safety violation that had resulted in a minor injury to a crew member.

Santa Fe district attorney Mary Carmack-Altwies said context such as this might affect any eventual decision to prosecute in the “Rust” shooting.

“It obviously could play into whether charges get filed or not,” she said.

Asked whether Emmy Award-winning Baldwin – who also served as a producer on the movie – could face criminal charges, she said it was not out of the question.

“All options are on the table. No one has been ruled out at this point,” she told a press conference.