SANTA FE, N.M. — Prosecutors announced that actor Alec Baldwin will be charged with involuntary manslaughter in the fatal shooting of a cinematographer who was killed on a New Mexico movie set.

Halyna Hutchins died shortly after being shot during rehearsals at a ranch on the outskirts of Santa Fe on Oct. 21, 2021. Baldwin was pointing a pistol at Hutchins when the gun went off, killing her and wounding the director, Joel Souza.

THIS IS A BREAKING NEWS UPDATE. AP’s earlier story follows below.

SANTA FE, N.M. (AP) — The Santa Fe district attorney will announce Thursday whether charges will be brought in the fatal 2021 film-set shooting of a cinematographer by actor Alec Baldwin during a rehearsal of the Western “Rust.”

Santa Fe District Attorney Mary Carmack-Altwies said the announcement will come in a statement and on social media, without public appearances by prosecutors.

“The announcement will be a solemn occasion, made in a manner keeping with the office’s commitment to upholding the integrity of the judicial process and respecting the victim’s family,” said Heather Brewer, a spokeswoman for the district attorney’s office.

Cinematographer Halyna Hutchins died shortly after being wounded by a gunshot during setup for a scene at the ranch on the outskirts of Santa Fe on Oct. 21, 2021. Baldwin was pointing a pistol at Hutchins when the gun went off, killing her and wounding the director, Joel Souza.

Santa Fe County Sheriff Adan Mendoza, who led the initial investigation into Hutchins’ death, described “a degree of neglect” on the film set. But he left decisions about potential criminal charges to prosecutors after delivering the results of a yearlong investigation in October. That report did not specify how live ammunition wound up on the film set.

Taking control of the investigation, Carmack-Altwies was granted an emergency $300,000 request for the state to pay for a special prosecutor, special investigator and other experts and personnel.

Baldwin — known for his roles in “30 Rock” and “The Hunt for Red October” and his impression of former President Donald Trump on “Saturday Night Live” — has described the killing as a “tragic accident.”

He sought to clear his name by suing people involved in handling and supplying the loaded gun that was handed to him on the set. Baldwin, also a co-producer on “Rust,” said he was told the gun was safe.

In his lawsuit, Baldwin said that while working on camera angles with Hutchins during rehearsal for a scene, he pointed the gun in her direction and pulled back and released the hammer of the weapon, which discharged.

New Mexico’s Office of the Medical Investigator determined the shooting was an accident following the completion of an autopsy and a review of law enforcement reports.

New Mexico’s Occupational Health and Safety Bureau has levied the maximum fine against Rust Movie Productions, based on a scathing narrative of safety failures, including testimony that production managers took limited or no action to address two misfires of blank ammunition on the set prior to the fatal shooting.

Rust Movie Productions continues to challenge the basis of a $137,000 fine by regulators who say production managers on the set failed to follow standard industry protocols for firearms safety.

The armorer who oversaw firearms on the set, Hannah Gutierrez Reed, has been the subject of much of the scrutiny in the case, along with an independent ammunition supplier. An attorney for Gutierrez Reed has said she did not put a live round in the gun that killed Hutchins, and she believes she was the victim of sabotage. Authorities said they have found no evidence of that.

Investigators initially found 500 rounds of ammunition at the movie set on the outskirts of Santa Fe — a mix of blanks, dummy rounds and what appeared to be live rounds. Industry experts have said live rounds should never be on set.

In April 2022, the Santa Fe Sheriff’s Department released a trove of files, including lapel camera video of the mortally wounded Hutchins slipping in and out of consciousness as a medical helicopter arrived. Witness interrogations, email threads, text conversations, inventories of ammunition and hundreds of photographs rounded out that collection of evidence.

State workplace safety regulators said that immediate gun-safety concerns were addressed when “Rust” ceased filming, and that a return to filming in New Mexico would be accompanied by new safety inspections.

The family of Hutchins — widower Matthew Hutchins and son Andros — settled a lawsuit against producers under an agreement that aims to restart filming with Matthew Hutchin’s involvement as executive producer.

“Rust” was beset by disputes from the start in early October 2021. Seven crew members walked off the set just hours before the fatal shooting amid discord over working conditions.

Hutchins’ death has influenced negotiations over safety provisions in film crew union contracts with Hollywood producers and spurred other filmmakers to choose computer-generated imagery of gunfire rather than real weapons with blank ammunition to minimize risks.