The mystery surrounding a missing New Mexico nuclear laboratory employee has taken a grim turn after investigators discovered her remains in a remote national forest nearly a year after she vanished.
Melissa Casias, a 54-year-old administrative assistant at Los Alamos National Laboratory, was found dead Monday in a secluded area of Carson National Forest, according to reports. Authorities said her remains were severely decomposed and largely skeletonized.
Casias disappeared on June 26, 2025, after leaving her home in Ranchos de Taos, a small community northeast of Santa Fe. Her disappearance sparked an extensive search and months of unanswered questions.
According to former homicide detective Thomas McNally, who was hired by Casias’ family to investigate the case, the mother of one was found propped against a tree with an abandoned firearm nearby. McNally told reporters that the remains showed a gunshot injury to the skull.
The investigator said one detail stood out to him: despite being exposed in the wilderness for months, the body reportedly showed little evidence of animal activity or disturbance.
McNally believes foul play may have been involved and has questioned aspects of the official investigation. He indicated that Casias’ family is considering legal action against authorities over their handling of the case.
Casias worked at Los Alamos National Laboratory, the historic facility established during the Manhattan Project and long associated with U.S. nuclear weapons research.
The circumstances surrounding her disappearance have puzzled investigators from the beginning.
According to reports, Casias allegedly erased records from her cellphones before leaving the devices and her identification behind at home. Earlier that day, she had driven her husband, Mark Casias, who also worked at the laboratory, to work.
McNally said the couple reportedly argued during the drive over a vape pen. After dropping her husband off, Casias allegedly returned home and told her daughter, Sierra, that she planned to work remotely.
Family members said nothing appeared unusual about her behavior.
“She looked totally normal,” McNally told reporters, citing the daughter’s account.
The last confirmed sighting of Casias occurred around 2:20 p.m. when she was seen walking east along State Road 518, roughly three miles from her home.
McNally has suggested she may have been trying to get away from someone when she disappeared, though authorities have not publicly confirmed that theory.
During the investigation, Casias’ husband reportedly suggested she may have left voluntarily and was involved with another man. McNally has disputed that narrative and said investigators should take a closer look at alternative explanations.
Authorities have not announced whether the death has been ruled a homicide, suicide or accidental shooting. The case remains under investigation as officials work to determine exactly what happened to the longtime laboratory employee in the final hours before she vanished.
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