Alec Baldwin. [Source: AP Entertainment]

Prosecutors formally dismissed an involuntary manslaughter charge against Alec Baldwin in the fatal 2021 shooting of a cinematographer on the set of the Western film “Rust, ” citing new evidence and the need for more time to investigate.

In a stunning turnaround for the 65-year-old A-list actor, special prosecutors Kari Morrissey and Jason Lewis filed the notice to dismiss the only remaining criminal allegation against Baldwin in the state District Court in Santa Fe. Prosecutors say the investigation of the shooting that killed Halyna Hutchins and injured director Joel Souza is ongoing.

An involuntary manslaughter charge against Hannah Gutierrez-Reed, the weapons supervisor in the film, is unchanged.

Friday’s court filing echoed early statements from prosecutors that new facts had been revealed that demanded further investigation and forensic analysis.

On Thursday, after Baldwin’s attorneys announced the decision, the special prosecutors said the “decision does not absolve Mr. Baldwin of criminal culpability and charges may be refiled.” They have declined further comment and only vaguely addressed the matter during a virtual status conference Friday in Gutierrez-Reed’s case.

Los Angeles-based entertainment litigator and defence attorney Kate Mangels, who is not involved in the “Rust” case, said opportunities for further charges against Baldwin are narrowing.

Authorities have not determined how live ammunition found its way into the .45-caliber revolver made by an Italian company that specializes in 19th-century reproductions.

Baldwin has said the gun fired accidentally after he followed instructions to point it toward Hutchins, who was behind the camera. Baldwin said he pulled back the hammer — but not the trigger — and the gun fired.

Authorities have not determined how live ammunition found its way into the .45-caliber revolver made by an Italian company that specializes in 19th-century reproductions.

An August FBI report on the agency’s analysis of the gun found that, as is common with firearms of that design, it could go off without pulling the trigger if force was applied to an uncocked hammer — such as by dropping the weapon.

The only way the testers could get it to fire was by striking the gun with a mallet while the hammer was down and resting on the cartridge, or by pulling the trigger while it was fully cocked. The gun eventually broke during the testing.

After reading the FBI report, retired Seattle police Detective Donald Ledbetter said it was unlikely the gun would have gone off without the trigger being pulled.

In March, “Rust” safety coordinator and assistant director David Halls pleaded no contest to a conviction for unsafe handling of a firearm and received a suspended sentence of six months of probation. He agreed to cooperate in the investigation of the fatal shooting.

A defence attorney for Halls said Friday that he is happy for Baldwin and also wishes the best for the Hutchins family.

When the manslaughter charges were announced in January, Santa Fe District Attorney Mary Carmack-Altwies said the case was about equal justice under the law and accountability in Hutchins’ death, regardless of the fame or fortune of those involved. She said the Ukrainian-born cinematographer’s death was tragic — and preventable.

A new legal team took over the prosecution of Baldwin and Gutierrez-Reed in late March after the original special prosecutor appointed in the case resigned.

When word of the dismissal came, Baldwin was at Yellowstone Film Ranch on the set of a rebooted “Rust” production, a representative for Rust Movie Productions said. Preparations for filming were underway at the film’s new location in Montana, 18 months after the shooting shut it down.