New Mexico identifies remains of nuclear lab employee missing for a year

Melissa Casias. Photograph: Find Melissa Mondragon Casias View image in fullscreen Melissa Casias. Photograph: Find Melissa Mondragon Casias New Mexico identifies remains of nuclear lab employee missing for a year Remains of Los Alamos employee Melissa Casias found alongside handgun in case that stirred online speculation Authorities in New Mexico have identified human remains which they recently discovered as those of a Los Alamos National Laboratory (LANL) employee who had been missing for more than a year. In a statement released over the weekend, state police said the remains belonged to Melissa Casias, a 53-year-old resident of Taos, New Mexico, who was last seen walking eastbound along a state highway on 26 June 2025. A hiker had discovered Casias’s remains in the McGaffey Ridge area of the Carson national forest on 28 May 2026, according to the statement from Saturday. “Investigators also learned that a handgun was located alongside the remains,” the state police statement said. Casias’s case was among that of about a dozen US scientists who were linked to space, defense and nuclear research – and had either died or disappeared in recent months. Some of those deaths have been ruled suicides or are otherwise clearly explainable. But the cases collectively have fueled a surge of online speculation and conspiracy theories, gaining congressional members’ attention and even prompting Donald Trump to direct the US government to investigate, saying it was all “pretty serious stuff”. Police said they identified Casias through coordination with the New Mexico medical investigator’s office. They said her cause and manner of death had not immediately been determined. Meanwhile, state police added, the investigation into Casias’s prior disappearance remains ongoing. In a July 2025 interview with NBC’s Dateline program, Casias’s husband, Mark, said he last saw her at about 6.15am on 26 June. She had dropped him off at the LANL where they both worked, a facility which helps maintain the US’s stockpile of nuclear weapons. According to Mark, Melissa said she planned to travel to another location within the laboratory’s 40-square-mile campus for a work assignment. He said he had asked her to return the family car by 11am because he needed it later that day. “That was pretty much the last I spoke to her that day,” Mark said of his wife, who told him she would return the car by the time he needed it. Investigators later learned that Melissa unexpectedly returned to the family’s home in Ranchos de Taos that morning, more than an hour from LANL. Melissa’s daughter, Sierra, told Dateline she recalled asking her mother why she had come back at about 7.45am, and Melissa replied that she had forgotten her badge. However, Mark told Dateline: “You’ve got to show your badge to get in – and … she showed her badge.” According to Sierra, Melissa appeared normal and said she had decided to “either work from home or call out for the day”. Later that day, Melissa delivered