Fact-checking claims about missing, dead scientists: Were they researching UFOs, nuclear weapons?

Social media users are posting about people who died or disappeared, claiming they are all scientists who knew secrets about nuclear research and unidentified flying objects.

They theorize that what happened to these people, who have died or disappeared since 2021, is concerted and not a coincidence. A viral April 14 X post read, "Can anyone explain what the deal is with all the missing scientists lately? We've had like 10 disappearances in the last two years. …What's the deal? It's too much to be coincidence. It's a legitimate anomaly. It's spooky."

A former lawmaker is also posting about it.

"There are 11 missing or dead or suicided scientists all linked to space or military programs and the FBI just now opened a ‘probe,’" former congresswoman Marjorie Taylor Greene posted April 22 on X.

Discussion about the scientists isn’t limited to social media. The FBI and the House Oversight Committee said they are investigating any potential connections among the missing and dead scientists and whether a national security threat exists. NASA, where several of the people were employed, said it is working with the relevant agencies. 

President Donald Trump told reporters April 16 that he had a meeting on the topic and "we’re gonna look at it over the next short period." 

We tracked 14 names that have surfaced in these posts. We examined their backgrounds and the circumstances of their deaths or disappearances, and some of the claims about potential connections among them don’t hold up. We also found that they were not all scientists. 

Here’s what’s been said and what we know.

The people did not all work together

Some social media posts claimed the people were professionally affiliated. An April 8 X post said, "Nearly all of them worked together — and died or vanished within the last two years."

That’s overstated. We found no evidence that "nearly all" were colleagues. 

These are their past employers and dates of death or disappearance:

NASA

• Michael David Hicks, died in July 2023.

• Frank Maiwald, died in July 2024.

• Monica Reza, disappeared in June 2025.

• Joshua LeBlanc, died in July 2025.

Los Alamos National Laboratory

• Anthony Chavez, disappeared in May 2025.

• Melissa Casias, disappeared in June 2025.

U.S. Air Force

• William McCasland, disappeared in February.

• Matthew Sullivan, died in 2024.

Other employers

• Steven Garcia, disappeared in August 2025; worked at the Kansas City National Security Campus.

• Carl Grillmair, died in February; worked at the California Institute of Technology and collaborated with NASA.

• Jason Thomas, disappeared in December 2025, found dead in March; worked at Novartis.

• Nuno Loureiro, died in December 2025; worked at the Massachusetts Institute of Technology.

• Amy Eskridge, died June 2022; founded the Institute for Exotic Science.

• Ning Li, died in 2021; worked at the University of Alabama in Huntsville, founded AC Gravity.

Unclear whether any of the people worked on classified nuclear or UFO programs

Some social media users claimed the people were targeted for their access to secret programs involving space and nuclear research. But that’s unsupported.

"TEN American scientists familiar with the US nuclear program are either missing, have died suddenly or have been murdered in the last 12 months. Nobody with power seems to think that’s in any way strange…" read one April 16 X post.

An April 7 X post read, "BREAKING: General William Neil McCasland and seven other scientists, now dead or missing, were linked to UFO and alien research & exposure, according to Tim Burchett." In recent interviews, Rep. Tim Burchett, R-Tenn., mentioned UFOs in connection with the missing or dead scientists.

We asked NASA what projects Hicks, Maiwald, Grillmair, Reza and LeBlanc worked on. The agency referred us to an April 20 X post from NASA Spokesperson Bethany Stevens, which said: "NASA is coordinating and cooperating with the relevant agencies in relation to the missing scientists. At this time, nothing related to NASA indicates a national security threat. The agency is committed to transparency and will provide more information as able."

Some of the people studied nuclear science but it’s unclear whether they were involved in classified programs; others worked at nuclear research facilities but not in scientific roles.

Here’s what we know about their professional backgrounds:

Of the group who worked at NASA, Hicks studied comets and asteroids. Maiwald worked on microwave radiometry and Earth science missions. Reza specialized in rocket materials. LeBlanc was an electrical engineer.

Those who worked at Los Alamos, a nuclear research facility, did not appear to have scientific roles. Casias worked as an administrative assistant, and Chavez as a construction foreman, USA Today reported.

Of the two affiliated with the U.S. Air Force, McCasland and Sullivan, McCasland’s wife wrote in a Facebook post that he "had access to some highly classified programs and information," but he retired from the Air Force almost 13 years ago. "It seems quite unlikely that he was taken to extract very dated secrets from him," she said.

She also said McCasland had a "brief association with the UFO community," when he worked as a consultant for a fiction book.

Rep. Eric Burlison, R-Mo., said Sullivan died before testifying in a federal whistleblower case on UFOs.

The others who worked at different institutions included Garcia, who was a government contractor and property custodian at the Kansas City National Security Campus, which develops nonnuclear components for nuclear weapons. The Hill reported that he had top security clearance at the facility. Grillmair, the astrophysicist, studied dark matter, Galactic structure, stellar populations and exoplanets, according to his CalTech page.

Thomas worked on chemical biology. Loureiro was a professor of nuclear science and engineering and of physics at MIT. Li and Eskridge studied anti-gravity.

Cause of deaths and disappearances probed

FBI Director Kash Patel told Fox News his agency will look for potential connections to foreign actors.

Rep. James Comer, R-Ky., has speculated that foreign adversaries such as China, North Korea, Iran or Russia may be involved because of their interest in the U.S. nuclear program.

Suspects have been arrested in some of the deaths. 

Claudio Manuel Neves Valente, a Portuguese national, fatally shot Loureiro and two students on Brown University’s campus in Rhode Island. Neves Valente died by a self-inflicted gunshot wound days later. The Justice Department said Neves Valente had been planning the shooting for at least six semesters, but released no motive. Neves Valente and Loureiro previously attended school together in Portugal.

Grillmair was shot at his home in February. A suspect was arrested and authorities believe the two did not know each other. 

Other cases involve unexplained disappearances. 

Casias disappeared on a day when she dropped off her husband at work, went back home, and brought lunch for her daughter at her workplace. Casias’ personal belongings remained at her home. New Mexico State Police said April 21 that the investigation continues, and the agency does not suspect foul play, the Santa Fe New Mexican reported. 

Chavez walked out of his home and disappeared. On April 21, CNN reported that a detective said there are no signs of foul play, but also no indications that he had planned to leave.

McCasland walked out of his home without his phone, prescription glasses and wearable devices, and disappeared.

LeBlanc left his phone, wallet and dog at his apartment. 

Reza’s body has not been recovered after she went missing during a hike. 

Thomas’ body was found in a lake after he went missing for three months. Thomas’ wife said he left his phone and wallet on the bathroom counter. Authorities did not suspect foul play.

And other cases had some details about the circumstances.

Garcia left his home on foot with a handgun. News outlets reported that Eskridge died of a self-inflicted gunshot wound. 

Sullivan died from a lethal mix of alcohol and drugs, the New York Post reported. 

Finally, a handful of the cases had no information available about the deaths. Li died in 2021 and Hicks died in 2023, but the reasons for their deaths are not public. 

We found no public information about Maiwald’s cause of death. 

PolitiFact Researcher Caryn Baird contributed to this report.