A lawyer for the assistant director on the movie Rust says she was told by her client "since the very first day" that Alec Baldwin did not pull the trigger on the gun that shot Halyna Hutchins dead. 

Lisa Torraco, told ABC News, that Baldwin's claim in his interview with George Stephanopoulos that he didn't pull the trigger was supported by assistant director Dave Halls. 

"Dave has told me since the very first day I met him that Alec did not pull that trigger," Torraco said. "His finger was never in the trigger guard." 

"Dave has told me since day one that it was an accident," Torraco said. "It was a pure accident — freak, awful accident [that] unfortunately killed somebody." 

Torraco said Hall is "heartbroken" over the tragedy and ensuing scrutiny. 

"It's very, very painful and very hard for him," she added. 

Baldwin, who was also a producer on the Western film, has detailed what happened that day in an interview that will air soon in the US. 

Clips from the interview show Baldwin claiming he "would never" point a gun and someone and shoot. 

"Someone put a live bullet in a gun, a bullet that wasn't even supposed to be on the property," Baldwin said. 

On October 21, Baldwin was holding an antique revolver during a dress rehearsal for Rust at the Bonanza Creek Ranch near Santa Fe, New Mexico, when the firearm discharged a live round, striking the film's cinematographer in the chest and striking the film's director, Joel Souza, in the shoulder. 

Santa Fe County Sheriff Adan Mendoza said an initial investigation determined that two other people had handled or inspected the loaded gun before it discharged – the film's armourer, Hannah Gutierrez-Reed, and Halls. 

A lawyer for Gutierrez-Reed has said she had no idea where the live rounds came from. 

Halls reportedly handed the Colt .45 revolver to Baldwin while proclaiming "cold gun", to let the crew know the gun had no live rounds in it. 

Hutchins, 42, died after being flown to University of New Mexico Hospital in Albuquerque. 

Souza, 48, was rushed via ambulance to hospital and released the next day. 

No charges have been filed in the case. 

"I will be shocked if criminal charges get filed against Mr Halls," Torraco said. "He had no responsibility, no liability and certainly not at the level of criminal liability."