SAG-AFTRA have issued a statement in support of Alec Baldwin.
The 65-year-old star could face up to 18 months in jail after being charged with involuntary manslaughter (negligent use of a firearm) or alternatively involuntary manslaughter (without due caution or circumspection) in relation to the death of cinematographer Halyna Hutchins on the set of Rust in October 2021, but his union have insisted it is not an actor's job to be a weapons "expert".
The body said in a statement: "To the extent that the charges filed on January 19 are based on an accusation of negligent use of a firearm predicated on this or any actor having a duty to inspect a firearm as part of its use, that is an incorrect assessment of the actual duties of an actor on set.
"An actor's job is not to be a firearms or weapons expert. Firearms are provided for use on set under the guidance of multiple expert professionals directly responsible for the safe and accurate operation of that firearm."
It went on to explain industry standards mean "an experienced, qualified armorer" must be responsible for "all handling, use, and safekeeping of firearms on set", as well as inspecting them before and after each use.
They added: "The guidelines do not make it the performer's responsibility to check any firearm. Performers train to perform, and they are not required or expected to be experts on guns or experienced in their use.
"The industry assigns that responsibility to qualified professionals who oversee their use and handling in every aspect. Anyone issued a firearm on set must be given training and guidance in its safe handling and use, but all activity with firearms on a set must be under the careful supervision and control of the professional armorer and the employer."
But a lawyer acting on behalf of Halyna's family claimed the statement "flies in the face of common sense and the law".
Gloria Allred said in her own statement: "The notion that an actor is not responsible if that actor holds a gun, points it at someone on a movie set, and discharges the weapon flies in the face of common sense and the law.
"Safety protocols may be considered at trial, but they are not the law.
"This indictment was the result of a careful assessment by the grand jury of all the facts and the law. It is important to respect the grand jury's decision to indict, and to allow the criminal justice system to proceed to trial where the case will be decided on its merits."