The remains of a New Mexico woman who disappeared nearly a year ago after leaving her home without explanation have been found, bringing a tragic development to a case that has drawn widespread attention.
New Mexico State Police confirmed Monday that remains discovered in Carson National Forest belong to Melissa Casias, a 54-year-old administrative assistant at Los Alamos National Laboratory who vanished on June 26, 2025.
According to investigators, Casias’ body was found over the weekend in the McGaffey Ridge area of the forest, approximately six miles from where she was last seen. A handgun was discovered near the remains, though authorities have not yet determined a cause of death or established exactly when she died.
The discovery was made by a hiker in an area where U.S. Forest Service crews have been conducting restoration work since late 2025. State police said the investigation remains active as forensic testing continues.
Casias worked at Los Alamos National Laboratory, the renowned research facility established during the Manhattan Project and still heavily involved in national security and nuclear weapons research. However, authorities have not indicated that her employment played any role in her disappearance or death.
The circumstances surrounding Casias’ disappearance have puzzled investigators and family members for nearly a year.
On the morning she vanished, Casias reportedly drove her husband, Mark, who also worked at Los Alamos, to the laboratory. Family members later told investigators that she said she had forgotten her security badge and planned to return home rather than continue to work.
According to her daughter, Sierra, Casias later delivered a sandwich and indicated she would be working from home that day.
Investigators said Casias left behind her cell phones and identification before disappearing. Family members also reported that records and information had been removed from her phones prior to her departure.
The last confirmed sighting of Casias came from surveillance footage that captured her walking east along State Road 518 near Ranchos de Taos at approximately 2:20 p.m. local time. She was alone at the time.
Authorities are now working to determine whether the handgun recovered near her remains belonged to Casias and how it may factor into the investigation.
The case gained additional attention because several other individuals with ties to defense, aerospace, and government-related work have disappeared or died in recent years. Among them was former Los Alamos employee Anthony Chavez, who vanished in May 2025, and retired Air Force Maj. Gen. William Neil McCasland, who disappeared from his Albuquerque home earlier this year.
While online speculation has linked some of these cases together, investigators have not publicly identified evidence connecting Casias’ death to any broader pattern.
For now, law enforcement officials remain focused on determining exactly what happened during Casias’ final days and providing answers to her family after nearly a year of uncertainty. The New Mexico Office of the Medical Investigator is expected to play a key role in determining the circumstances surrounding her death as the investigation moves forward.
