Alec Baldwin didn't realize he fired a live round at Halyna Hutchins until after the sheriff's office showed him the bullet, his lawyers say

• Alec Baldwin didn't initially comprehend that he fired a bullet on the "Rust" set, his lawyer says.
• He found it "outside the realm of all possibility" that his gun would carry a live round, according to a new filing.

Alec Baldwin didn't comprehend that he fired a live round at "Rust" cinematographer Halyna Hutchins, killing her, until hours later when a member of the Santa Fe's Sheriff's Office showed him the bullet after an interview, according to arbitration paperwork filed by his attorney on Friday.

According to the filing, Baldwin found it "unthinkable" that his gun would have a live bullet in it after the person responsible for checking it declared it as "cold."

"He was shocked," the filing says. "In his mind, it was outside the realm of all possibility that a live bullet could have been present on the ranch property or on the prop truck, let alone in the gun itself."

The detailed account of Baldwin's actions and thoughts on the "Rust" set on the day of the shooting were included in an arbitration case between the actor and the movie's production company.

The death of Hutchins and the injury of the movie's director Joel Souza have led to a web of lawsuits between the people involved in the movie's production and their family members, including a wrongful death lawsuit that Hutchins' husband Matt filed against Baldwin.

In Baldwin's arbitration claim, his lawyer says the "Rust" production company should be responsible for his personal legal defenses stemming from the shooting.

According to the Santa Fe Sheriff's office, the gun passed through the hands of armorer Hannah Gutierrez-Reed and first assistant director David Halls, who handed it to Baldwin and yelled "cold gun," indicating did not contain live rounds.

Baldwin's new filing says that he coordinated with Hutchins about where to point the gun as they prepared the scene.

"Baldwin asked Hutchins whether she wanted to see him cock the gun, as the script required. She responded yes," reads the filing by attorney Luke Nikas. "Baldwin tipped the gun down somewhat so that the lens of the camera would be able to focus on his hand's action on the top of the gun. While performing this action, Baldwin asked Hutchins, 'Am I holding it too far down?' and 'Do you see that?' Hutchins responded that she could see Baldwin's action from her angle."

Baldwin then pulled back the gun's hammer but didn't cock it, the filing says, but the gun went off anyway.

The filing says the actor and other members of the crew left while medical officials helped Hutchins and Souza as "a sense of panic and confusion descended" upon the set.

According to the document, Baldwin and other members of the production team didn't comprehend that a bullet was fired.

"Baldwin thought Hutchins may have fainted or had a heart attack. He was also confused about why Souza was screaming in pain, unaware that a live bullet had struck him," the document says. "One individual suggested that a stone might have been lodged in the gun and discharged."

The filing says that the suggestion that a live round was in the gun was "quickly dismissed by others as farfetched" because Reed and Halls were both responsible for checking guns to confirm they didn't have live ammunition.

Later, Baldwin spoke with members of the Santa Fe County Sheriff's Office for nearly two hours.

The filing says that at the end of the interview, the interviewer "slid her phone across the table and showed him a photograph of the object that had just been removed from Souza's shoulder at the hospital, a .45 caliber slug."

"Baldwin recognized the object as a live bullet, and he finally began to comprehend what had transpired on the set of Rust that day," the document says. "He was shocked."

Lawyers for the "Rust" production company did not immediately respond to a request for comment by Insider on Friday.

Baldwin's lawyer also included text message exchanges between Matt Hutchins and Baldwin in the filing, arguing they demonstrate Matt Hutchins never believed the actor was responsible for his wife's death.

Hutchins family attorney Brian Panish told Insider that the disclosure of those messages was Baldwin's way of "trying to avoid liability and accountability for his reckless actions."

"It is shameful that Baldwin claims Hutchins' actions in filing a wrongful death lawsuit derailed the completion of 'Rust,'" Panish said. "The only action that ended the film's production was Baldwin's killing of Halyna Hutchins."