A New Mexico sheriff involved in investigating the movie set shooting involving Alec Baldwin said Thursday that the matter is being treated as a criminal investigation. “I’d be careful using the word ‘accident,’” said Sante Fe County Sheriff Adan Mendoza during a Fox News interview. “This is obviously a tragedy and it was avoidable, so right now it’s a criminal investigation.” During the filming of a scene in the western drama “Rust” last week, Baldwin, fired a gun that he allegedly believed wasn’t loaded, striking and killing cinematographer Halyna Hutchins and injuring director Joel Souza. Baldwin hasn’t been charged in the case, and he’s issued few public statements about the matter since then. It’s not clear whether charges will be filed against Baldwin or anyone else, Mendoza said, noting that the investigation is still in its early stages. But he told Fox News that “we haven’t ruled anybody out in regards to …