Conspiracy theories about a series of dead and missing scientists caused the FBI to get involved

Since 2022, at least 10 scientists involved in sensitive projects of the US government or the US Aeronautics and Space Administration (NASA) have died or gone missing, most recently William Neil McCasland, a 68-year-old Air Force major general who retired in 2013.

McCasland left his home in New Mexico in February, carrying a gun and wallet, and no trace has yet been found. He is an aerospace engineer who has held many sensitive positions related to technology and space programs of the US Department of Defense.

Other cases that have attracted a lot of attention are Monica Jacinton Reza, an aerospace engineer specializing in rocket engines, who disappeared in June 2025 while climbing a mountain in Los Angeles, fusion and plasma physics expert Nuno Loureiro of the Massachusetts Institute of Technology, and astrophysicist Carl Grillmair of the California Institute of Technology, who were all shot to death at home in December 2025 and February 2026.

The series of incidents has sparked growing speculation on social media that some people may have been targeted in an effort to conceal what the government knows about UAP/UFOs or were targeted by America’s enemies.

According to experts, similar theories always exist on social networks, but rarely spread enough to attract US officials to consider.

“A typical conspiracy theory just appears and then quickly subsides,” said Joseph Uscinski, a professor at the University of Miami who specializes in studying conspiracy theories. “This time, the story becomes different because there are government agents directly involved in the investigation.”

Right-wing commentator Tim Pool in 2025 devoted an entire episode of the podcast he founded to Loureiro’s murder, suggesting that it might be related to the physicist’s research on clean energy. Officials said the suspect was Claudio Valente, a former engineering classmate of Loureiro. A day earlier, Valente opened fire at Brown University, killing two students.

Subsequently, some content creators, including conservative writer Jessica Reed Kraus, hypothesized that Loureiro’s death could be related to the murder of astrophysicist Grillmair.

“The post exploded as soon as I posted it on Instagram,” Kraus said, adding that it was the most shared content on her account. “And then everything just spread.”

This information fueled long-simmering speculations about the possibility of a connection between the events. The disappearance of retired Air Force general McCasland made the theories spread even more strongly, especially after a local US Federal Bureau of Investigation (FBI) office joined the search.

“What is happening to our space scientists?!”, a famous UFO account on X wrote, with a collage of photos of Loureiro, Grillmair and McCasland.

In March, a speculative post went viral in the UFO community. The content of the post links 9 different scientists, including Loureiro, Grillmair, McCasland, Reza and Melissa Casias – a Los Alamos laboratory employee in New Mexico state who has been missing since June 2025. Los Alamos is also a name that often appears in conspiracy theories about UFOs.

By mid-March, this theory began to spread to mainstream media, appearing in NewsNation and the New York Post, before being further exploited by Fox News and the Daily Mail.

“We don’t know if these incidents are related or not, but the fact that so many top scientists have been murdered or disappeared in less than a year is clearly a very alarming sign,” Fox News host Jesse Watters said. Watters noted that McCasland’s disappearance occurred shortly after President Donald Trump announced he would release UFO-related records.

Commentator Pool continued to question whether these scientists were involved in UFO research or some “special weapons project”.

These conspiracy theories spreading on the Internet caught President Trump’s attention. The White House boss said in early April that he had participated in a meeting to discuss the issue.

“I hope these are just random events,” Mr. Trump said. “But among them there are very important people, we will investigate and clarify.”

On April 20, the FBI announced the opening of an investigation to find any connection, if any, between the disappearances and deaths of about 10 scientists and government employees in the past few years. The FBI will coordinate with the US Department of Defense, the Department of Energy and local law enforcement to find answers.

The House Oversight Committee said on the same day that it would conduct its own investigation, and asked the Department of Defense, Department of Energy, FBI and NASA to provide a summary report on “the disappearances and deaths of individuals with access to sensitive US scientific information”.

Meanwhile, some family members of the above scientists rejected the conspiracy theory.

“The public should understand that scientists die just like anyone else, and should not overinterpret this,” said the family of Amy Eskridge, a researcher specializing in quantum computing and gravity adjustment research who died in 2022.

Michael David Hicks, a physicist at NASA’s Jet Propulsion Laboratory who studied comets and asteroids, died in 2023. Hicks’ daughter said he had been struggling with health problems for a long time and that recent online speculation made the family feel uneasy.

“Based on what I know about my father, there’s no logic to him being involved in the federal investigation that people are speculating about,” she told the publication. CNN. “I don’t understand why my father’s death is linked to the disappearances of other scientists.”