The investigation into the death of Melissa Casias, an administrative assistant at Los Alamos National Laboratory (LANL), has taken a complex turn following the discovery of her remains nearly a year after her disappearance. Casias, 53, was last seen on June 26, 2025, and her skeletal remains were found in New Mexico's Carson National Forest on May 28, 2026.
New details indicate that Casias took her toothbrush and thyroid medication before leaving her home, actions that independent investigators suggest might suggest an intention to survive. Her remains were discovered near a handgun, though her family has stated the weapon did not belong to her. The New Mexico Office of the Medical Investigator has not yet officially determined a cause of death.
Initial reports suggested Casias suffered a gunshot wound to the head, but authorities have not publicly confirmed this. An initial CT scan of the remains reportedly did not reveal any projectiles. The absence of a recovered bullet has become a point of scrutiny, with experts noting that the type of ammunition used could influence whether a projectile remains with the body.
Casias disappeared after dropping her husband, Mark Casias, also a LANL employee, at the facility. She reportedly told her daughter that she was returning home to retrieve her forgotten security badge, but she also dropped off her work and personal phones at their residence. These phones were later found wiped clean of data. The last confirmed sighting of Casias was on surveillance footage walking alone on State Road 518, approximately three miles from her home.
Former FBI Assistant Director Chris Swecker previously expressed concern that Casias' disappearance could be linked to a pattern involving individuals with access to sensitive government research. He suggested that her role at LANL, even as an administrative assistant, might have made her a target. However, Casias' family and private investigators have contested the extent of her access, noting that she had reportedly lost her security clearance due to financial difficulties.