Mendoza said Baldwin, 63, is "obviously the person that fired the weapon" and is "an active part of the investigation."
Santa Fe District Attorney Mary Carmack-Altwies would not rule out charges being brought against Baldwin, the film's star and a producer. "All options are on the table at this point. We cannot answer that question yet."
"No one has been ruled out at this point," Carmack-Altwies said Wednesday.
An affidavit from the sheriff's office revealed Gutierrez told investigators that on the day of the incident, she checked the "dummies" and ensured there were not “hot” rounds in the firearm.
Gutierrez added that as the crew broke for lunch, the firearms were taken back and secured inside a safe on a set "prop truck." During the lunch break, she stated the ammo was left on a cart and not secured.
Gutierrez said no live ammo was "ever kept" on the set, according to the affidavit.
The affidavit said that Halls recalled seeing the firearm before continuing the rehearsal.
When asked about safety protocols, he told investigators: “I check the barrel for obstructions, most of the time there’s no live fire, she (Hannah) opens the hatch and spins the drum, and I say 'cold gun' on set,” indicating a weapon that doesn't contain ammunition.