Mysterious Deaths, Disappearances Of CA Scientists A 'Grave' National Security Concern: What To Know

The mysterious deaths and disappearances of at least ten scientists — including four who worked in California — has attracted the attention of federal authorities, who worry that the incidents may represent "a grave threat" to national security due to the nature of their work.

Recent media reports have connected the scientists' disappearances and deaths to what the Daily Mail called "a dark pattern surrounding U.S. secrets." The reports have prompted multiple federal authorities into action.

The House Oversight Committee on Monday requested information from the FBI and other federal agencies "about the scientists and other personnel connected to U.S. nuclear secrets or rocket technology who have died or mysteriously vanished in recent years."

Rep. Eric Burlison, the Missouri Republican who chairs the committee's subcommittee on energy policy, told NewsNation this week that American researchers would be an "easy target" for adversaries.

“I would not be surprised if our adversaries, China, Russia, Iran, or any other adversary saw an opportunity to take out some of our nation’s top scientists,” Burlison said.

Last week, President Donald Trump told reporters he had been briefed on the matter, which he said "was pretty serious stuff" and vowed that there would be an investigation into the situation. The White House press secretary promised "no stone will be untuned in this effort."

"The White House is actively working with all relevant agencies and the FBI to holistically review all of the cases together and identify any potential commonalities that may exist," Karoline Leavitt wrote on social media.

In light of the recent and legitimate questions about these troubling cases, and President Trump’s commitment to the truth, the White House is actively working with all relevant agencies and the FBI to holistically review all of the cases together and identify any potential… pic.twitter.com/SJ9thaFegh

— Karoline Leavitt (@PressSec) April 17, 2026

A NASA spokesperson last week said the agency 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."

Jen Golbeck, a professor at the University of Maryland who studies conspiracy theories, said the idea of a sinister connection between tragedies involving scientists is a common trope within conspiracy theory communities.

“There are a lot of people who work for national labs and universities and government research centers and some of them will go missing or commit suicide or die,” she said. “Any year you could take a bunch of those and name them as something sinister if you wanted to."

There are 10 primary cases that have been called out in the media, including several people connected to the Los Alamos National Laboratory in New Mexico.

The most recent case was the disappearance of William Neil McCasland, a 68-year-old retired Air Force general who vanished from his New Mexico home on foot in February with only a handgun. He previously led a research laboratory at Wright-Patterson Air Force Base, which was home to a project in the 1950s and 60s that looked into UFO sightings, USA Today reported.

UFO enthusiasts have long identified McCasland as a key U.S. government leader in the research of such topics. Burlison on Fox News described McCasland as the "UFO general."

McCasland’s wife, Susan Wilkerson, wrote in a Facebook post on March 6 responding to online rumors that since his retirement 13 years ago, McCasland “has had only very commonly held clearances” and that “it seems quite unlikely that he was taken to extract very dated secrets from him.” She added that although he “had a brief association with the UFO community,” he does not have any privileged knowledge about aliens.

Four of the cases involve people connected to NASA's Jet Propulsion Laboratory (JPL) and the California Institute of Technology (Caltech) in Los Angeles County.

JPL is a federally funded research and development center managed by Caltech. It's one of the nation’s leading hubs for space exploration and advanced engineering, responsible for designing and operating robotic missions for NASA, including Mars rovers and deep-space probes. (The lab traces its roots to a 1930s group of rocket pioneers including prominent occultist Jack Parsons, an unconventional origin story that has long sparked speculation about its early history.)

Caltech is a top-tier scientific institution known for its cutting-edge research in fields ranging from aerospace and physics to artificial intelligence and quantum science.

Here's a look at disappearances and deaths tied to those institutions:

Michael David Hicks

The House Oversight lawmakers say the string of recent deaths and disappearances began with the 2023 death of Michael David Hicks, a former JPL scientist.

Hicks died at 59; his obituary did not disclose his cause of death.

Hicks published over 80 scientific papers and was part of teams that helped NASA understand the properties of comets and asteroids. Among his work was on the DART Project, which aimed to see if humans could deflect dangerous asteroids away from earth, the Daily Mail reported.

Hicks died about a year after leaving JPL, where he had worked since 1998, according to the publication.

Frank Maiwald

Frank Maiwald worked at JPL from 2001 to 2024, the year he died at age 61. No cause of death has been released publicly.

The German-born scientist specialized in microwave radiometry. He contributed to various projects, including one that takes sea-level measurements to gain insight into climate change, USA Today reported.

Monica Reza

In June 2025, another JPL scientist — 60-year-old Monica Reza — disappeared while hiking in the Angeles National Forest. She has never been found.

Reza was hiking the Mount Waterman Trail with two other people when she disappeared. Authorities and volunteers conducted extensive searches but have been unable to find her, the New York Post reported.

Reza, who uses the last name Jacinto in her career, was the director of the NASA lab's Materials Processing Group, USA Today reported.

She is the co-creator of Mondaloy, a nickel-based “super-alloy” used in rocket engines. That work brought her into the orbit of McCasland — the person who most recently disappeared — when he oversaw the Air Force group that funded research in the early 2000s into advanced materials for space vehicles and weapons, the Post reported.

Carl Grillmair

Carl Johann Grillmair, 67, was fatally shot on the front porch of his home in a remote part of the Antelope Valley community of Llano in February. A suspect was arrested and charged with murder in that case, although a possible motive for the crime has not been released.

Grillmair's work included research using NASA's Spitzer Space Telescope and focused on galactic structure, dark matter and stellar populations, according to his Caltech biography.

Colleagues say his research helped scientists identify water signatures on planets outside the solar system. He was also known for discovering stellar streams — trails of stars left behind by disrupted star clusters and dwarf galaxies — which provided important insight into how the Milky Way formed and evolved, KTLA reported.

Material from the Associated Press and City News Service was used in this report.