In the pics, the Baldwins pose with their six children -- Carmen, 8, Rafael, 6, Leonardo, 5, Romeo, 3, Eduardo, 1, and Lucia, 8 months -- in varying costumes including a spider, a Viking, and an '80s fitness instructor.
"Parenting through this has been an intense experience, to say the least," Hilaria wrote. "Today, we rallied to give them a holiday. Last min costumes…a little hodge-podge…but they were so happy and that warmed my mama heart."
"Happy Halloween, from the Baldwinitos," she continued. "They give us ❤️. We send you ❤️🎃"
Following the incident, Alec posted a statement, assuring the public that he was fully cooperating with police.
"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," his statement read. "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. My heart is broken for her husband, their son, and all who knew and loved Halyna."
Around the same time, a source told ET that Alec "is beside himself."
"He is incredibly devastated and sick to his stomach over what happened," the source said. "He is still processing everything and dealing with a lot of grief and shock."
"My heart is with Halyna. Her husband. Her son. Their family and loved ones. And my Alec," she wrote. "It's said, 'there are no words' because it's impossible to express the shock and the heartache of such a tragic accident. Heartbreak. Loss. Support."
Santa Fe County Sheriff Adan Mendoza told media on Oct. 29 that it was "too early" to discuss possible charges being filed. "The investigation will continue and if the sheriff's office determines during our investigation that a crime has occurred and probable cause exists, an arrest or arrests will be made and charges will be filed," he explained.
Then, on Oct. 30, Alec spoke on camera about the incident for the first time, addressing the paparazzi in Vermont.
"She was my friend," he said of Halyna, in video obtained by TMZ. "The day I arrived in Santa Fe to start shooting I took her to dinner with Joel, the director. We were a very, very well-oiled crew shooting a film together, and then this horrible event happened."
Alec also noted that he's spoken to Halyna's husband, Matthew, saying, "The guy is overwhelmed with grief."
"There are incidental accidents on film sets from time to time, but nothing like this. This is a one in a trillion episode. It's a one in a trillion event," Baldwin said. "He's in shock. He has a 9-year-old son. We are in constant contact with them, because we're very worried about his family, his kid."
As for if he believes production on Rust will resume, Baldwin said, "No, I don't."
The fatal shooting was reportedly not the first time the Rust set was unsafe. Multiple reports noted that, prior to Halyna's death and Joel's injury, union crew members walked off set to protest "poor" working conditions. As noted in the armorer Hannah Gutierrez-Reed's recent statement, there was also an incident that included the misfiring of a gun.