The Santa Fe District Attorney on Wednesday said there was no proof that someone deliberately put a live round into the gun used by Alec Baldwin when he accidentally shot dead a cinematographer on a movie set last month.

Mary Carmack-Altwies told "Good Morning America" in an interview that investigators still had no idea how live rounds made their way to the "Rust" set in October, and that the probe could take months to complete.

The possibility of sabotage was raised last week by the attorney for Hannah Gutierrez, who was in charge of weapons on the set of the Western movie "Rust" in New Mexico.

"I know that some defense attorneys have come up with conspiracy theories and have used the word sabotage. We do not have any proof," Carmack-Altwies said.

Asked whether she thought sabotage was a possibility, she said "No."

Cinematographer Halyna Hutchins was killed on Oct. 21, and director Joel Souza was wounded when a gun Baldwin had been told was safe fired off a live bullet, investigators have said. Other live rounds have also been found on the set.

"We still don't know how they got on the set," Carmack-Altwies said, referring to the live rounds. "And how they got there I think will be one of the most important factors going into a charging decision."

The District Attorney said the local sheriff's department was still investigating the case and that no decisions on charges were likely to come soon.

The film's producers have said they are conducting their own investigation into the fatal shooting.