Firearms expert Lucien Haag gave evidence in court on Tuesday during the trial of the film's armourer, Hannah Gutierrez, who is charged with involuntary manslaughter and tampering with evidence.

Ms Hutchins died after a gun held by Baldwin went off during rehearsals on the film set on the outskirts of Santa Fe, New Mexico, in October 2021.

The Hollywood star, also a producer on the film, has pleaded not guilty to a charge of involuntary manslaughter and will face a separate trial in July. He has previously claimed the gun went off without him pulling the trigger, and has not appeared in court for Gutierrez's hearing.

On Monday, an FBI expert told the court in Santa Fe the revolver used by Baldwin on set was fully functional with safety features when it arrived at an FBI laboratory for testing. The expert said he had to strike the fully-cocked gun with a mallet and break it in order for it to fire without depressing the trigger.

Jurors shown gun experimentation

Giving evidence the following day, Mr Haag provided a lengthy demonstration of the workings of a single-action Colt revolver, like the gun held by Baldwin, and safety features that prevent a fully cocked hammer from striking and firing ammunition unless the trigger is depressed.

He saw no evidence the gun was broken or modified before it was tested by the FBI, he told the court.

The jury watched a video of his experimentation with Baldwin's gun, as the hammer was pulled back and released multiple times - and caught each time by a safety notch before it could strike the ammunition chamber to fire the gun.

"If you're trying to cock the gun and you lose your grasp on it, the hammer falls - that safety notch captures it," Mr Haag said.

Lawyers for Gutierrez, who denies the charges against her, say problems on the Rust set were beyond her control and have claimed there were shortcomings in the collection of evidence and debriefings after the fatal shooting. They claim she has been made a scapegoat.

How did live rounds get on set?

During Tuesday's hearing, jurors also heard about the issue of how live rounds - which have been forbidden on movie sets for more than 100 years - got on to the Rust set in the first place.

Prosecutors allege Gutierrez was unprofessional and unknowingly brought six live rounds on set and failed to spot them.

The court has seen video footage of the armourer telling detectives in an interview after the shooting that the live round came from an ammunition box provided by a props supplier about a week earlier.

Asked in court by New Mexico state prosecutor Kari Morrissey whether the statement was correct, Santa Fe County Sheriff's Office detective Alexandra Hancock said it was not.

Detective Hancock testified that she investigated the props supplier initially as the potential source of live ammunition, but found he never went to the Rust set and that a search of his property in Albuquerque turned up live rounds that did not match those found at the scene.

Defence lawyers have not yet had the opportunity to cross-examine the detective.

Baldwin has previously said firearms safety was the responsibility of weapons handlers, not an actor - although he is also one of the film's producers.

Gutierrez's trial continues.