'Rust' Shooting: Sheriff Says 'It's Too Early' to Press Charges in Halyna Hutchins' Death

A new search warrant affidavit obtained by ET also reveals more details about the moments that led up to the fatal shooting.

During a press conference on Wednesday about the fatal shooting on the set of Rust last Thursday, Santa Fe County Sheriff Adan Mendoza and Santa Fe District Attorney Mary Carmack-Altwies said that their investigation was still ongoing, and that "all options are still on the table" when it comes to possibly filing charges in the death of cinematographer Halyna Hutchins.

In the tragic incident that occurred, Alec Baldwin discharged a gun that was inadvertently loaded with a live round that struck and killed Hutchins and hospitalized director Joel Souza.

"During the initial investigation, it was determined that actor/producer Alec Baldwin was the person that fired the weapon," Mendoza said during the press conference. "We identified two other people who handled and or inspected the loaded firearm prior to Baldwin firing the weapon. These two individuals are armorer Hannah Gutierrez-Reed and assistant director David Halls. All three individuals have been cooperative in the investigation and have provided statements."

"During this process, we determined there were a limited amount of movie set staff present in the area where the actual incident took place, although there were approximately 100 people on set," he continued. "Through the execution of search warrants, we have collected about 600 items of evidence. These include but are not limited to three firearms, approximately 500 rounds of ammunition and several pieces of clothing and possessions. We believe that we have in our possession the firearm that was fired by Mr. Baldwin."

Mendoza said it was "too early" to talk about possible charges being filed.

"The investigation will continue and if the Sheriff's Office determines during our investigation that a crime has occurred and probable cause exists, an arrest or arrests will be made and charges will be filed," he said.

Carmack-Altwies agreed, noting that the investigation was still ongoing.

"I must emphasize that a complete and thorough investigation is critical to DA review," she said. "We take the corroborated facts and evidence and connect it to New Mexico law. And we are not at that juncture yet. If the facts and evidence and law support charges, then I will initiate prosecution at that time."

"All options are on the table -- no one has been ruled out," she also said.

Meanwhile, more details are emerging about the moments that led up to the fatal shooting. According to a search warrant affidavit obtained by ET, in an interview, Gutierrez-Reed stated on the day of the incident, she checked the "dummies" and ensured they were not "hot" rounds. As the crew broke for lunch that day, she said the firearms were taken back and secured inside a safe on a "prop truck" on set. During lunch, she stated that ammunition was left on a cart on set and not secured. The affidavit continues that after lunch, a woman named Sarah Zachary pulled the firearms out of the safe inside the track, and handed them to her. Gutierrez-Reed stated that there were only a few people that have access and the combination to the safe, and that no live ammunition is ever kept on set.

According to the search warrant affidavit, when Halls was asked about the safety protocol on set in regard to firearms, he stated, "I check the barrel for obstructions, most of the time there's no live fire, she (Gutierrez-Reed) opens the hatch and spins the drum and I say cold gun on set." The affidavit states that when Gutierrez-Reed showed Halls the firearm before continuing rehearsal, he could only remember seeing three rounds. He advised that he should have checked all of them, but didn't, and couldn't recall if she spun the drum.

On Tuesday, ET spoke with firearms expert Steve Wolf, who provided insight into how an incident like this could occur. He explained that, while the gun was used in the film as a prop, it was still very much a real, working firearm and the term "prop gun" is a misnomer, and has been misused in reports on the incident.

"The gun that Helena was shot with was not a prop gun. A prop gun is a gun that has either been modified to only accept blanks, or has been specifically manufactured to only accept blanks," Wolf explained. "If bullets came out of this gun it was not a prop gun. It was a real gun that was being used as a prop in the movie."

Watch the video below for more.