Another woman connected to 'highly sensitive' US scientific secrets has disappeared

 Since June 2025, at least six people with ties to nuclear research, missile technology, or U.S. defense programs have gone missing or died under unexplained circumstances. Melissa Casias, an administrative assistant at a prominent New Mexico nuclear research facility, is the second woman in that group. She has been missing since June 26, 2025, and has not been located since.

Casias worked at Los Alamos National Laboratory in New Mexico, a facility with Manhattan Project origins that remains central to U.S. nuclear research. Her husband, Mark, also worked there. On June 26, 2025, she dropped him off at LANL and drove away. She never reported for her own shift and did not work from home that day. Her supervisor confirmed she never showed up.

Surveillance footage captured Casias walking alone eastbound along State Road 518 in Talpa, New Mexico, around 2:18 p.m., roughly three miles from her home. The footage, recorded by a camera at a local business, remains the last known sighting of her. New Mexico State Police said it was difficult to determine whether she appeared distressed. She had no wallet, phone, or keys with her.

Her Last Known Movements Left Investigators and Family With Few Answers

After Casias was last seen on State Road 518 that afternoon, her family returned home to find her purse, wallet, and keys left inside. Sgt. Breceda confirmed to Dateline that both phones had been factory reset with all data wiped, the work phone on the kitchen table and the personal phone in her home office. No physical evidence of her whereabouts has been found since.

In the weeks after she vanished, family members found evidence suggesting Casias had been dealing with financial difficulties they were unaware of. Crime Junkie, a true crime podcast, has reported that Casias allegedly lost her national security clearance at LANL due to the family's financial situation, a circumstance that could have made her vulnerable to blackmail. LANL told the Daily Mail it had cooperated fully with the investigation, but did not address the clearance reports.

New Mexico State Police told Dateline that the evidence gathered suggests Casias may have left on her own, though investigators have not ruled out foul play. "Nobody has been cleared at this point," Sgt. Breceda wrote. More than 125 community volunteers participated in organized searches covering hundreds of acres across Carson National Forest and surrounding areas. The family is offering a $5,000 reward for information leading to her safe return.

Her Case Is Now Tied to a Broader Pattern of Missing and Dead Defense Figures

Casias's disappearance came just four days after NASA scientist Monica Reza went missing during a hike near Mount Waterman in California's Angeles National Forest on June 22, 2025. Reza directed the Materials Processing Group at NASA's Jet Propulsion Laboratory and invented Mondaloy, a high-performance metal developed for advanced missile and rocket engines. She was just 30 feet from two hiking companions when she vanished.

Both women had indirect ties to retired Air Force General William Neil McCasland, 68, who vanished near Quail Run Court NE in Albuquerque on February 27, 2026. McCasland oversaw the Air Force Research Laboratory at Wright-Patterson from 2011 to 2013, when it funded Reza's work, and had previously led Kirtland Air Force Base, which works closely with LANL. He left home without his phone, glasses, or other devices and took only boots and a .38-caliber revolver.

At least two other researchers have died since late 2025 under circumstances that have drawn scrutiny, though no confirmed link to the other cases has been established. Astrophysicist Carl Grillmair, 67, was shot on his front porch in California on February 16, 2026, with no motive made public. Nuclear fusion researcher Nuno Loureiro was also shot dead in his Brookline, Massachusetts, home in December 2025.

A Former FBI Official Says Federal Investigators Cannot Treat These as Separate Cases

Former FBI Assistant Director Chris Swecker, who spent 24 years with the bureau, told the Daily Mail these cases cannot be treated as isolated missing-persons investigations. "When I look at three missing scientists in critical technology areas, what I come up with is it has to be investigated fully by the FBI," Swecker said. He argued that treating each case as a standalone matter risks obscuring connections that federal investigators have yet to fully examine.

Swecker also noted that administrative assistants at high-clearance facilities often have access to the same sensitive information as the researchers they support. "In a classified lab, they would basically be in the know on what's going on," he said. "And it wouldn't be the first time their administrative assistant has been targeted." He was particularly troubled by Reza's case, noting she vanished just 30 feet from two companions with no trace ever found.

Swecker said his focus is not on UFO theories, even as some have speculated online, but on national security. "I'm particularly concerned about their involvement in the missile technology," he told the Daily Mail. "I think you have to pull out all the resources necessary to look for links and look for potential espionage activities." Anyone with information about Casias is asked to contact the New Mexico State Police at 505-425-6771.