US actor Alec Baldwin fired a vintage Colt pistol loaded with a live lead round in the accidental fatal shooting last week of a cinematographer on the New Mexico set of his movie Rust, authorities say.
Santa Fe County Sheriff Adan Mendoza and District Attorney Mary Carmack-Altwies held a briefing six days after Baldwin accidentally shot and killed cinematographer Halyna Hutchins during a rehearsal for a scene inside a church at the filming location in New Mexico.
No one has been charged.
Mendoza and Carmack-Altwies said it was too early to discuss charges but said charges would be filed if warranted.
"No one has been ruled out at this point," Carmack-Altwies said referring to potential charges.
She said the investigation is not yet concluded.
Authorities have the firearm used in the shooting, the sheriff said.
Mendoza said what is thought to be additional live rounds have been found on the set but they would be subject to testing by ballistics experts.
Mendoza said the gun was a Long Colt revolver.
"It's a suspected live round that was fired but it did fire from the weapon and it did cause injury. That would lead us to believe it was a live round," he said.
The sheriff said Baldwin has been co-operative in the investigation.
"He's obviously the person that fired the weapon," Mendoza said.
"Right now, he is an active part of this investigation."
The sheriff also said there was "complacency" on the set regarding firearms.
The shooting has sent shockwaves through Hollywood, prompting a debate about safety protocols in film and television - including whether certain types of guns used as props should be banned - and working conditions on low-budget productions.
Authorities have said in court filings that Baldwin last Thursday was handed what he thought was a "cold," or safe, gun by the film's assistant director David Halls, who took it from a cart used by Hannah Gutierrez, who was employed to oversee firearms and their safety in a job called an armourer.
The gun instead contained what police called "live rounds," and a shot hit Hutchins in the chest and director Joel Souza, standing behind her, in the shoulder.
Hutchins was transported by helicopter to the University of New Mexico Hospital, where she was pronounced dead.
Souza was treated at a hospital and released.
The lead round was recovered from Souza, Mendoza said.
Baldwin, 63, serves as a co-producer of Rust, a film set in 1880s Kansas, and plays an outlaw grandfather of a 13-year-old boy convicted of an accidental killing.
Production had been taking place at the Bonanza Creek Ranch, located south of Santa Fe, and has been halted.
Baldwin has called it a "tragic accident" and, like other cast and crew, is co-operating with police.
The film's producers have hired the law firm Jenner & Block to investigate the shooting.
In a letter sent to cast and crew on Tuesday night, the film's production team said Jenner "will have full discretion about who to interview and any conclusions they draw".
Baldwin was drawing a revolver across his body and pointing it at a camera while rehearsing when the weapon fired, according to a sheriff's department affidavit released on Sunday.
Detectives recovered two boxes of "ammo," "loose ammo and boxes" as well as "a fanny pack w/ammo," along with several spent casings, according to a court filing.
Before the incident, camera operators had walked off the set to protest working conditions, according to the affidavit.
Australian Associated Press