What the ‘Rust’ Jury Heard About How Live Rounds Got on a Film Set

Ever since a real, live bullet discharged from the gun that Alec Baldwin was rehearsing with on the set of the film “Rust” in 2021, killing the cinematographer and wounding the director, one question has vexed everyone involved: How did live ammunition end up on a film set, where — all agree — it absolutely should never have been?

The film’s armorer, Hannah Gutierrez-Reed, was found guilty on Wednesday of involuntary manslaughter in the death of the cinematographer, Halyna Hutchins, and faces up to 18 months in prison. The jury found that Ms. Gutierrez-Reed, 26, had behaved negligently by failing to check that all of the rounds she loaded into Mr. Baldwin’s revolver were dummies, which are inert rounds that look real but cannot be fired.

The question of where the live ammunition came from in the first place has hung over the case from the start. The original investigation by the Santa Fe County Sheriff’s Office did not reach a conclusion on where the live rounds had come from.

During the trial, prosecutors sought to convince jurors that it was Ms. Gutierrez-Reed who was responsible for bringing the rounds onto the set. The defense asserted that Ms. Gutierrez-Reed, who did not testify, was not at fault, and tried to focus attention on the movie’s primary weapons and ammunition supplier, Seth Kenney, who took the stand and denied responsibility.

Here is what emerged during the trial about the live ammunition, and where it may have come from.

Prosecutors zeroed in on a box of rounds from the set.

When investigators arrived at the chaotic scene shortly after the shooting, on Oct. 21, 2021, Ms. Gutierrez-Reed showed a lieutenant from the Santa Fe County Sheriff’s Office a cart where she kept guns and ammunition and drew his attention to a box of ammunition where she said that she had retrieved the rounds she put in Mr. Baldwin’s revolver.