The ongoing investigation following an incident in which Alec Baldwin fired a prop gun that killed cinematographer Halyna Hutchins on set has found that the actor’s weapon contained a live round.

Baldwin fired the prop weapon on the set of the film Rust, which resulted in the death of Hutchins and injuries to director Joel Souza on Thursday (October 21), authorities say.

“I think the facts are clear – a weapon was handed to Mr Baldwin. The weapon is functional and fired a live round killing Ms Hutchins and injuring Mr Souza,” Santa Fe County Sheriff, Adan Mendoza said at a press conference.

He also confirmed that a “lead projectile” has been recovered from Souza’s shoulder, which is believed to have been what caused the death of Hutchins.

The investigation has revealed that of the recovered 500 rounds of ammunition, there was “a mix of blanks, dummy rounds and what we are suspecting is live rounds”, according to Mendoza.

“Right now we’re going to determine how those got there, why they were there – because they shouldn’t have been there,” he said.

Since the shooting, Baldwin shared a statement on social media, expressing his “shock and sadness regarding the tragic accident that took the life of Halyna Hutchins, a wife, mother, and deeply admired colleague of ours”.

He added: “I’m fully cooperating with the police investigation to address how this tragedy occurred and I am in touch with her husband, offering my support to him and his family.”

Production on the movie was halted indefinitely to comply with police investigations. It is reported that Baldwin went willingly to the sheriff’s office to provide a statement. “No charges have been filed in regard to the incident,” said sheriff’s office spokesperson Juan Ríos.

Now, official court documents state that assistant director Dave Halls unwittingly handed Balwin the prop gun, indicating that it was safe by shouting “cold gun!” (via the BBC).