Remains of missing Los Alamos National Laboratory staffer found in New Mexico, left behind wiped phone

The remains of a staffer who went missing in 2025 have been found. Human remains had been found by a hiker in a New Mexico national forest in late May, and those remains have been identified as belonging to Melissa Casias.

Per NBC News, the discovery of the remains in the McGaffey Ridge area of Carson National Forest was reported on Thursday. The New Mexico Medical Investigator’s Office identified the remains as those of Casias, an administrative assistant at the Los Alamos National Laboratory. 

New Mexico State Police said in a statement on Saturday, "Investigators also learned that a handgun was located alongside the remains." Casias was reported missing on June 26 after she failed to show up for her. Her supervisor called her husband, looking for her. 

Mark Casias, her husband, said that she had dropped him off at the laboratory where they both work earlier on the day she went missing. He said that she had told him she was going to another location within the lab to finish a work task, but did not return as planned. 

Sierra, the couple’s daughter, said she later found her mother’s keys, as well as her cellphone that had been wiped and reset to factory settings in the family’s home in Ranchos de Taos. Casias was found around 6 miles from the home, and had been seen walking along the highway nearby the day she was reported missing. 

Mark Casias said he went through documents following his wife’s disappearance that showed she was under a large amount of stress at the time. While police didn’t rule out foul play, State Police Sgt. Ricardo Breceda said in 2025 that it "may be the case" that Casias had disappeared of her own volition. 

Casias is one of around a dozen people connected to sensitive US nuclear or aerospace research who have died or disappeared in recent years. The FBI said in April that it was examining the matter. The agency said it is "spearheading the effort to look for connections into the missing and deceased scientists,” and is coordinating with the Department of Energy, Department of War, and state and local law enforcement partner agencies. The White House also said at the time that it would be reviewing the matter.