In his first social media post since Halyna, 42, was killed Thursday in an accidental shooting on the set of the movie Rust, Matthew, 48, shared a brief yet heartfelt message alongside a trio of images of the couple and their 9-year-old son Andros.
"We miss you, Halyna!" Matthew captioned the Instagram post. The widower received an outpouring of support in the comments section, many wishing Halyna "rest in peace."
The cinematographer and director Joel Souza were accidentally shot on Thursday by Rust star and producer Alec Baldwin during a camera test at the Bonanza Creek Ranch set in New Mexico.
Halyna died from her injuries after being airlifted to the University of New Mexico Hospital. Souza, 48, was treated at the Christus St. Vincent Medical Center in Santa Fe and released on Friday.
On Friday, Matthew told Insider that "there are words to communicate the situation."
"I am not going to be able to comment about the facts or the process of what we're going through right now, but I appreciate that everyone has been very sympathetic," he added. "I think that we will need a little bit of time before we can really encapsulate her life in a way that is easy to communicate."
In an interview with Daily Mail the same day, Matthew said Baldwin, 63, was "very supportive" when the two spoke following the tragedy.
Also on Friday, Baldwin confirmed in a statement that he had been in touch with Matthew. The actor added that he was "fully cooperating" with police as they investigated the incident and how it occurred.
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"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 wrote, in part.
He added: "My heart is broken for her husband, their son, and all who knew and loved Halyna."
A source later told PEOPLE that the ordeal has been "incredibly difficult" and "devastating" for Baldwin, who was still trying to get his head around everything that happened."