Hannah Gutierrez-Reed, the armorer on the set of "Rust", faces two charges of involuntary manslaughter for the fatal shooting of cinematographer Halyna Hutchins.
Criminal charges against Alec Baldwin, the actor who fired the gun, were dropped but may be reinstated pending ongoing investigation.
Witnesses claim Gutierrez-Reed was possibly hungover from heavy drinking and marijuana use during the shoot.
Despite her alleged state, Gutierrez-Reed is accused of loading a live round into the gun used in the fatal scene.
Gutierrez-Reed's attorney, Jason Bowles, accuses the prosecution of character assassination and claims the focus should be on first assistant director, Dave Halls.
Halls, who handed the gun to Baldwin after declaring it safe, pleaded guilty to negligent use of a firearm and faces probation.
Bowles claims that Gutierrez-Reed was overburdened on set and had requested more time to focus on weapons, a request which was denied.
Armorer Scott Rasmussen, who had initially been approached to work on "Rust", may testify on Gutierrez-Reed's behalf.
Baldwin shared an Instagram post marking the end of filming "Rust" in Montana, praising the cast and crew for completing the project.
Cinematographer Bianca Cline stepped in to complete the film and is reportedly donating her salary to charity.