Questions grow over death of Los Alamos Lab assistant Melissa Casias

A handgun found near Melissa Casias’s remains has deepened questions around the Los Alamos National Laboratory assistant’s death, even as New Mexico State Police have not released a cause or manner of death. Casias, 53, was reported missing after disappearing from northern New Mexico in June 2025, and her family now says the case still demands a full accounting.

Casias worked as an administrative assistant at Los Alamos National Laboratory. She was last seen walking alone on State Road 518 near Talpa, New Mexico, wearing a backpack, after visiting her daughter’s workplace and failing to return home that night. Family members later found that her ID, purse and cell phones had been left behind, a detail that intensified the search for her in the months that followed.

Her remains were found on May 28, 2026, in the McGaffey Ridge area of Carson National Forest by a hiker. Family members said the area had already been searched, raising new concerns about how the case was handled and what evidence may still be missing from the public record. State police announced her identity but said at the time that investigators had not yet determined how she died.

The Casias case now sits within a wider federal review. The FBI is leading an effort to look for possible connections among 10 missing or deceased scientists and staff members who worked at sensitive nuclear or space technology laboratories. Casias was the second person employed at Los Alamos National Laboratory to go missing last year, after Anthony Chavez, adding to the scrutiny around whether separate disappearances share any pattern at all.

Family members, speaking through the Find Melissa Mondragon Casias social media page, said they will continue pursuing answers and justice. For Los Alamos County, where the lab remains central to the local economy and civic life, the unanswered questions around Casias’s death now extend beyond a single case to the thoroughness and transparency of the institutions charged with resolving it.