Conspiracy theories about missing scientists have captured public attention in the United States, fuelling a firestorm of speculation that has spread from fringe internet forums to the White House briefing room. At the centre of the storm are at least 11 researchers and technicians with links to space, defence and nuclear programmes who have died or disappeared in recent years. The theories, which range from Chinese state espionage to alien abduction, have prompted Republican lawmakers to demand an investigation and forced President Donald Trump to promise he would look into the matter.
The origins of the rumour lie in the sudden disappearance of a retired United States Air Force major general. William “Neil” McCasland, 68, walked out of his home in Albuquerque, New Mexico, on 27 February. He left behind his phone and glasses, took his .38 revolver, and has not been seen since. As a former commander of the Phillips research site at Kirtland Air Force Base — a facility focused on space vehicles and directed-energy technologies — McCasland’s vanishing quickly attracted the attention of the UFO community. Lieutenant Kyle Woods of the Bernalillo County Sheriff’s Office told reporters that nothing had been ruled out and that investigators were pursuing all possible leads, but added: “I appreciate that there’s a community that wants to go down the rabbit hole of UFOs. I don’t have a way with which to pursue that.”
Into the void left by hard facts poured accounts of other missing or dead scientists, each with a real or imagined connection to national security or space work. The list soon included Michael David Hicks, a Nasa Jet Propulsion Laboratory (JPL) scientist who spent more than two decades studying near-Earth asteroids and comets before dying from undisclosed causes in 2023, aged 59. Monica Reza, director of JPL’s materials processing group and co-inventor of the Mondaloy superalloy used in rocket engines, vanished while hiking in the Angeles National Forest in June 2025. She was about 30ft behind a companion when she disappeared; her body was never found. Astrophysicist Carl Grillmair, 67, was shot dead on his porch in Llano, California, in February 2026 — a suspect, Freddy Snyder, has been charged with murder, carjacking and burglary. Nuno Loureiro, a professor at MIT’s Plasma Science and Fusion Center, was killed by gunshot at his home in December 2025 in an attack linked to Cláudio Manuel Neves Valente, who had also carried out a shooting at Brown University days earlier. Chemical biologist Jason Thomas disappeared in December 2025; his remains were discovered in a Massachusetts lake in March 2026. Another name added to the theories was Amy Eskridge, an Alabama-based researcher who claimed to be working on “gravity-modification research” and who died by suicide in 2022. Franc Milburn, a man who claims to be a former British intelligence officer, told NewsNation that Eskridge had texted him saying: “If you see any report that I killed myself, I most definitely did not.” Her family, however, maintains there is no mystery and points to chronic pain. Two additional workers affiliated with the Los Alamos National Laboratory are also cited in congressional correspondence as having died or gone missing. The research briefing also names Frank Maiwald, a JPL physicist who died in July 2024 aged 61 with no cause disclosed, and Melissa Casias, whose family believes she intentionally disappeared due to stress and does not wish to be found.
The conspiracy takes hold
The stories were seized upon by rightwing media and quickly reached the mainstream. President Trump himself called the concerns “pretty serious stuff” and said he would look into them. Republican congressmen James Comer of Kentucky and Eric Burlison of Missouri sent a letter to the FBI, the Department of Energy, Nasa and the Department of Defense demanding an investigation into a “possible sinister connection” between the incidents. “If the reports are accurate, these deaths and disappearances may represent a grave threat to US national security and to US personnel with access to scientific secrets,” they wrote, adding a separate letter to Secretary of Defence Pete Hegseth noting that Reza and McCasland may have had a “close professional connection”.
The FBI confirmed it is “spearheading the effort to look for connections into the missing and deceased scientists” and is working with other agencies. The White House has also directed federal agencies to investigate. Yet individuals close to the inquiries have stated that they see no links between the disparate cases. “We can only go off the facts,” said Lieutenant Woods, echoing a sentiment that has done little to calm the feverish speculation.
No evidence, but plenty of traction
Experts argue that the notion of a coordinated plot — whether involving foreign powers, UFOs, or some combination of the two — collapses under scrutiny. Out of more than two million scientific researchers in the United States, or an estimated 700,000 with top-secret aerospace and nuclear clearances, a handful of deaths and disappearances over several years is statistically unremarkable. Many of the cases have straightforward explanations: Grillmair’s murder is the subject of an active criminal prosecution; Loureiro’s death has been linked to a specific assailant; Thomas’s family said he was depressed; Eskridge’s family insists her suicide was unrelated to any conspiracy. McCasland’s wife, Susan McCasland Wilkerson, has become the most effective debunker, pointing out that her husband retired 13 years ago and had no special knowledge of UFOs or the Roswell incident. “It seems quite unlikely that he was taken to extract very dated secrets from him,” she wrote. With a wry tone she added: “Maybe the best hypothesis is that aliens beamed him up to the mothership. However, no sightings of a mothership hovering above the Sandia Mountains have been reported.”
Yet the conspiracy refuses to die. Why? The answer, say analysts, lies in the specific climate of anxiety that has settled over American public life — and the fertile ground it provides for unproveable narratives. Greg Eghigian, professor of history and bioethics at Penn State and author of After the Flying Saucers Came, draws a distinction between this latest flare-up and the New Jersey drone scare of late 2024, when a private contractor later admitted to causing sightings during a government test. “It’s one of those things that gets folded into other kinds of concerns and conspiracy theories that are out there about science and medicine that have been circulating around since Covid,” he said. The theories “fold neatly into the decades-old notion that UFOs are spotted around nuclear facilities and some of these facilities may be masking UFO-related projects.”
For Eghigian, the missing scientists narrative occupies “a sweet spot for UFO lore because you have all the elements that have always been there — the military, state secrets, nuclear facilities and technologies, and fear of figures that are missing. What is it? Are they being abducted? Assassinated because they know too much? The seeds of this were planted decades ago.” The convergence comes at a moment of heightened national security anxiety, a time when reports of UFO sightings and alien abductions tend to spike. Social media and artificial intelligence — what one source calls “AI slop and social media disinformation” — amplify every morsel of conspiratorial connection, creating an appetite that can never be satisfied. Podcasters such as Joe Rogan have lent their platforms to the speculation, suggesting the disappearances might involve “plasma technology, whatever the fuck that is”.
Even the suicide of prominent UFO researcher David Wilcock, 53, who shot himself outside his home in Boulder County, Colorado, has been absorbed into the narrative. Tennessee congressman Tim Burchett responded to a social media post announcing Wilcock’s death with the words “Not cool” and told the Daily Mail: “I just don’t think there’s any chance that this is just all coincidental.” It is a sentiment that, in the absence of evidence, continues to drive public fascination — even as the families of the dead and missing insist, over and over, that there is nothing to see.
