The gun that shot and killed cinematographer Halyna Hutchins and injured director Joel Souza on the set of Alec Baldwin's film Rust was previously used by crew members for target practice, TMZ reports.
Sources connected to the production tell the outlet that the prop gun had been used recreationally for target practice away from the set prior to the deadly shooting.
On Thursday, authorities responded to an incident at the New Mexico set of Rust around 1:50 p.m. local time following 911 calls indicating "an individual had been shot on set," the Santa Fe Sheriff's Department wrote in a press release obtained by PEOPLE.
Upon further investigation, the sheriff's department learned that Hutchins, 42, and Souza, 48, were "shot when a prop firearm was discharged" by Baldwin, 63, during a camera test.
Hutchins was airlifted to the University of New Mexico Hospital where she died from her injuries, according to the sheriff's department. Souza was hospitalized, but his reps told Deadline he has since been released.
Halyna Hutchins/ instagram Halyna Hutchins on the set of 'Rust'
On Friday, International Alliance of Theatrical Stage Employees (IATSE) Local 44, a union for propmasters, sent an email out to its members stating that the gun contained "a live round," per IndieWire.
The IATSE Local 44 email contradicted an earlier report that the gun Baldwin was using on set contained blanks. IATSE did not immediately respond to a request for comment from PEOPLE.
In the wake of the tragedy, a source told PEOPLE that Baldwin was "hysterical and absolutely inconsolable for hours" following the shooting: "Everyone knows this was an accident, but he's absolutely devastated."
A source also told PEOPLE that the actor "is still trying to get his head around everything that happened. This has been devastating. It's been incredibly difficult."
Baldwin first spoke out regarding the incident on Friday morning, issuing a two-part statement on Twitter.
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Jim Spellman/Getty Images Alec Baldwin
"There are no words to convey my shock and sadness regarding the tragic accident that took the life of Halyna Hutchins, a wife, mother and deeply admired colleague of ours," the actor began.
"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," he continued. "My heart is broken for her husband, their son, and all who knew and loved Halyna."
The Rust film set has been shut down and production indefinitely paused following Hutchins' death, according to the production company, Rust Movie Productions, LLC.
"The entire cast and crew has been absolutely devastated by today's tragedy, and we send our deepest condolences to Halyna's family and loved ones," the company said in a statement on Thursday.
"We have halted production on the film for an undetermined period of time and are fully cooperating with the Santa Fe Police Department's investigation. We will be providing counseling services to everyone connected to the film as we work to process this awful event."