More than a year after she vanished without a trace, the remains of a New Mexico woman who worked at one of the nation’s most prominent nuclear research facilities have been discovered in a remote forest, raising new questions about what happened in the days before her disappearance.
According to the New York Post, Melissa Casias, 54, was found dead Monday in an isolated section of Carson National Forest, local authorities said.
Casias had been missing since June 26, 2025.
The discovery came after months of uncertainty surrounding the fate of the Los Alamos National Laboratory employee, whose disappearance baffled investigators and devastated her family.
Thomas McNally, a former homicide detective hired by the family to investigate the case, told The Daily Mail that Casias’ body was found in a “skeletonized” state. He said her remains were positioned against a tree and that a gun was located nearby.
McNally also noted that the remains showed no apparent evidence of animal activity or disturbance despite having been left in the forest for an extended period.
The investigator said he believes foul play played a role in Casias’ death. He also suggested the family may pursue legal action against the New Mexico State Police, alleging the investigation was mishandled.
Casias worked as an administrative assistant at Los Alamos National Laboratory, the facility originally established during World War II as part of the Manhattan Project and long associated with U.S. nuclear weapons research.
According to reports, Casias left behind her phones and identification on the day she disappeared after allegedly wiping data from the devices.
Earlier that day, she had driven her husband, Mark, who also worked at Los Alamos, to the laboratory. McNally told the outlet the couple argued during the drive over a vape pen.
Afterward, Casias reportedly returned home. Her daughter, Sierra, told police her mother appeared normal when she arrived.
“She looked totally normal. Sierra said everything was fine. She didn’t look weird,” McNally told the outlet.
Casias reportedly dropped off a sandwich and told her daughter she intended to work from home.
She was later seen walking east along State Road 518, approximately three miles from the family’s home, around 2:20 p.m.
McNally said he believes Casias “was fleeing somebody” when she disappeared.
During the investigation, her husband reportedly suggested to police that Casias “was running around with a boyfriend somewhere,” a theory McNally said authorities accepted.
Casias’ disappearance drew additional attention because it followed several other missing-person cases involving individuals connected to defense, aerospace, or nuclear-related work.
Among them was former Los Alamos employee Anthony Chavez, 79, who disappeared in May 2025. Aerospace engineer Monica Reza vanished while hiking in California in June 2025. Government contractor Steven Garcia disappeared from Albuquerque in August 2025.
Retired Air Force Maj. Gen. William Neil McCasland, who was involved in advanced aerospace research, also remains missing after disappearing from his Albuquerque home in February.
The circumstances surrounding Casias’ death remain under investigation.
