Gun in fatal on-set 'Rust' shooting was mechanically improper, source says

The special prosecutors' decision to drop the charges against Alec Baldwin over the fatal on-set "Rust" shooting was made, at least in part, because investigators found the gun that fired to be mechanically improper, a source familiar with the matter told ABC News.

Baldwin, 65, had been charged with two counts of involuntary manslaughter after fatally shooting cinematographer Halyna Hutchins, 42, on the New Mexico set of the Western in October 2021. The actor was practicing a cross-draw when the gun fired, striking the cinematographer.

Investigators effectively conducted an autopsy of the Colt .45 revolver and found that there were worn joints and that the trigger control was not functioning properly, according to the source.

It became evident to prosecutors the gun could fire without pressure on the trigger, according to the source.

On Thursday, the newly appointed special prosecutors in the case confirmed charges have been dropped against the actor, though noted their investigation remains "active and ongoing."

Baldwin told ABC News' George Stephanopoulos in an exclusive interview in the wake of the shooting that he had "no idea" how a live bullet got onto the set of his film, but that he "didn't pull the trigger" on the firearm that killed Hutchins.

"I would never point a gun at anyone and pull the trigger at them, never," Baldwin told Stephanopoulos.

Baldwin's attorneys said Thursday that they were "pleased" with the decision to dismiss the case against Baldwin and "encourage a proper investigation into the facts and circumstances of this tragic accident."

Kari Morrissey and Jason Lewis were appointed special prosecutors in the case last month in a shakeup that saw the Santa Fe District Attorney Mary Carmack-Altwies and state Rep. Andrea Reeb step down from prosecuting the case.

In a statement Thursday night, Morrissey and Lewis said that "new facts were revealed that demand further investigation and forensic analysis in the case."

"Consequently, we cannot proceed under the current time constraints and on the facts and evidence turned over by law enforcement in its existing form. We therefore will be dismissing the involuntary manslaughter charges against Mr. Baldwin to conduct further investigation," they said. "This decision does not absolve Mr. Baldwin of criminal culpability and charges may be refiled. Our follow-up investigation will remain active and ongoing."

The film's armorer, Hannah Gutierrez-Reed, was also charged with two counts of involuntary manslaughter over Hutchins' death. The special prosecutors said Thursday that the charges against Gutierrez-Reed "remain unchanged." A status conference is scheduled for Friday afternoon.

Amid the yearlong investigation into the fatal shooting, an FBI forensic report found that the gun could not have been fired without pulling the trigger. Though Baldwin's attorney said at the time that the report was being "misconstrued."

"The gun fired in testing only one time -- without having to pull the trigger -- when the hammer was pulled back and the gun broke in two different places," the attorney, Luke Nikas, said. "The FBI was unable to fire the gun in any prior test, even when pulling the trigger, because it was in such poor condition."

This is a developing story. Please check back for updates.