Lab worker who vanished last year found dead in New Mexico national forest

Remains found in a New Mexico national forest have been identified as those of Melissa Casias, a worker at the Los Alamos National Laboratory who disappeared last year, authorities announced over the weekend.

New Mexico State Police said the remains were discovered by a hiker last week in the McGaffey Ridge area of the Carson National Forest, a massive expanse of wilderness that is within driving distance of Taos, the city where she was from. A handgun was found near the remains, state police said. Casias would have been 53.

The medical examiner’s office will continue to conduct tests to determine the cause and manner of her death, according to police. When they shared her identity Saturday, neither of those rulings had been made yet.

Casias was employed as an administrative assistant at the Los Alamos National Laboratory, her niece, Jazmin McMillen, previously told CBS News. She was the second person employed at the laboratory to go missing last year, following the disappearance of Anthony Chavez, 78, in May. 

Both are among a group of at least 10 missing or deceased scientists and laboratory staff who worked at sensitive nuclear or space technology labs, law enforcement officials have told CBS News. The FBI is leading an investigation into possible connections between the cases.

Casias was reported missing on June 26, 2025, after failing to show up to work or return home that evening after visiting her daughter, state police said. Family members later found her personal belongings, including her ID, purse and cell phones, which raised concerns about Casias’ whereabouts and wellbeing. 

Casias was last seen walking alone on a highway, wearing a backpack, McMillen told CBS News, after she said she reviewed the surveillance footage that captured her aunt herself.

An investigation into Casias’ disappearance has been ongoing since she was reported missing and will continue, according to state police. They said that they “extend their deepest condolences” to Casias’ relatives “during this difficult time.”

The family released a statement of their own through a social media page called Find Melissa Mondragon Casias, which is dedicated to her case. The statement, also released Saturday, was additionally obtained and published by CBS affiliate KRQE.

“We confirm that the remains found in Rio Chiquito are Melissa,” they said in the statement. “There will be more information to come but what we can tell you now is she was located in an area previously searched. This is a lot to process, our hearts are heavy and we fully intend to continue to pursue answers for justice.”