The case drew attention in part because of the odd circumstances of her disappearance. Authorities previously stated Casias left behind her identification along with her work and personal phones, which had been wiped clean. Investigators said factory resets appeared to have been performed, erasing records that might have shown who she spoke with before she vanished.
Surveillance footage last captured Casias walking alone eastward on State Road 518, roughly three miles from her home in Ranchos de Taos, at about 2:20 p.m. The day she disappeared. The forest location where her body was uncovered sits roughly five to six miles from that road, authorities said.
State police said the investigation is ongoing. Authorities are still working the scene, including tracing the handgun and determining whether Casias owned it.
Her disappearance has also been discussed alongside other New Mexico missing-person cases involving people with ties to defense or sensitive research facilities, though authorities have not publicly linked those cases.
The remains of a missing Los Alamos National Laboratory employee have been identified in northern New Mexico, nearly 11 months after she walked away from her home and disappeared, state police remarked.
New Mexico State Police stated they have positively identified the remains as Melissa Casias, 54, who was last seen June 26, 2025. Her body was located in the McGaffey Ridge area of the Carson National Forest, about six miles from the last place investigators believe she was seen walking.
Police stated a hiker discovered the body. Investigators also discovered a handgun near the remains. The Office of the Medical Investigator will determine Casias’ cause and manner of death, along with an estimated time of death.
Casias worked as an administrative assistant at Los Alamos National Laboratory, a facility founded during World War II’s Manhattan Project and tied ever since to national security and nuclear weapons research.
Investigators say a gun was identified near the remains of Melissa Casias, who worked at the Los Alamos National Laboratory.
Casias had dropped her husband, also a Los Alamos employee, at the lab roughly 70 miles from their home earlier that morning, police have noted. Based on her husband, Mark, she had her security badge when she dropped him off. Investigators said she later told family members she needed to return home after forgetting the badge and would work from home.
Former FBI Assistant Director Chris Swecker previously told the Daily Mail that an administrative assistant at a high-clearance facility can be exposed to sensitive information and could be targeted. But Casias’ family and private investigators have questioned how much access she had, saying she had was defeated her security clearance due to financial troubles.
The area where Casias was disclosed is part of a large U.S. Forest Service restoration project cleared in 2023 covering roughly 30,000 acres south of Taos. Crews began active work in the area in December 2025, including thinning and timber harvesting aimed at reducing wildfire risk and improving watershed health.
State police said more information will be released as the medical investigator’s office completes its work.
