Deaths, Disappearances Of US Scientists Spark Federal Probe: Are The Cases Connected?

Last Updated:April 24, 2026, 09:08 IST

Around 10 cases linked to sensitive US research are under federal scrutiny, as agencies probe possible connections.

A cluster of deaths and disappearances involving individuals connected — directly or indirectly — to US scientific and defence-linked research has drawn attention from the highest levels of the federal government.

The cases, which span several years and involve roughly 10 individuals, have prompted the Federal Bureau of Investigation (FBI) to lead a coordinated effort to determine whether any links exist. The FBI said it “is spearheading the effort to look for connections into the missing and deceased scientists," working alongside the Department of Energy, the Department of Defense, and state and local law enforcement agencies.

The White House has also confirmed that it is reviewing the cases with multiple federal agencies. US President Donald Trump said the matter could turn out to be coincidental. “Hopefully, I don’t know, coincidence, whatever you want to call it," he told reporters, adding that officials would examine it “over the next short period."

At the same time, the Republican-led House Committee on Oversight and Government Reform has opened an inquiry, citing concerns that some of the individuals may have had access to “sensitive US scientific information." In letters seeking briefings from agencies including the FBI, Department of Energy, Department of Defense and NASA, lawmakers said the reports “raise questions about a possible sinister connection."

White House press secretary Karoline Leavitt has said the administration is working with “relevant" agencies and the FBI, adding that “no stone will be unturned."

Is There Any Evidence Of A Pattern Or Connection?

Despite the attention, authorities have not established any confirmed link between the cases.

Officials say the list brings together individuals from different fields, institutions and roles — ranging from senior scientists and engineers to administrative staff and contractors. A review of the cases shows inconsistent ties to scientific research and varying levels of access to sensitive information.

The circumstances surrounding each case also differ sharply. Some involve confirmed homicides with suspects identified, while others are missing persons cases where investigators have said there is no evidence of foul play. In several instances, families and authorities have pointed to medical issues or personal circumstances.

NASA, which is linked to multiple individuals on the list, said it is cooperating with the investigation but does not currently see a national security risk. “At this time, nothing related to NASA indicates a national security threat," spokesperson Bethany Stevens said.

Outside government, scepticism has also emerged. Daniel Engber, an editor at The Atlantic, described the reaction as “unbelievably dumb," while sociologist Robert Bartholomew wrote that the situation reflects a tendency to see patterns where none may exist, noting that the United States has thousands of scientists and that deaths and disappearances occur regularly.

Who Are The Missing Individuals?

Several of the cases under scrutiny involve individuals who remain untraced.

Among them is William Neil McCasland, a retired Air Force major general who once commanded the Air Force Research Laboratory. He was last seen leaving his home in Albuquerque, New Mexico, in February 2025. Authorities issued a “Silver Alert," citing unspecified medical issues and noting he had previously experienced “mental fog," though they said there was no evidence of foul play at the time. Items including a revolver were also reported missing from the residence.

His wife, Susan McCasland Wilkerson, rejected speculation linking his disappearance to classified work, writing that while he had once had access to sensitive information, he had been retired for over a decade and held only “commonly held" clearances. “It seems quite unlikely that he was taken to extract very dated secrets from him," she said.

Also missing is Monica Jacinto Reza, a 60-year-old aerospace engineer and director of a materials processing group at NASA’s Jet Propulsion Laboratory. She disappeared in June 2025 while hiking in the Crescenta Valley area north of Los Angeles.

Two individuals linked to Los Alamos National Laboratory — a key US nuclear research facility — also remain missing. Melissa Casias, an administrative assistant, was last seen walking along a highway in New Mexico in June 2025 after leaving her belongings at home. Authorities have said no foul play is suspected.

Anthony Chavez, a construction foreman at the same laboratory, disappeared a month earlier in May 2025. Local police have said there is no information linking his disappearance to his work.

Another case involves Jason Thomas, a Massachusetts-based chemical biology scientist. He went missing in December 2025, and his body was found in a lake in March 2026. Authorities said no foul play was suspected. His wife told local media he had disappeared shortly after losing both his parents.

Which Scientists Have Died In Recent Years?

The list also includes several deaths that have drawn renewed attention.

Michael David Hicks, a research scientist who worked at NASA’s Jet Propulsion Laboratory from 2000 to 2022, died on July 30, 2023. His cause of death was not disclosed publicly. His daughter, Julia Hicks, told CNN that he had been dealing with medical issues.

“From what I know of my dad, there’s no train of logic to follow that would implicate him in this potential federal investigation," she said. “I don’t understand the connection between my dad’s death and the other missing scientists."

“I can’t help but laugh about it, but at the same time, it’s getting serious," she added, saying she had been “shaken up" by the renewed attention.

Frank Maiwald, a specialist in microwave radiometry who contributed to Earth science missions including satellite-based sea-level monitoring, died in 2024 at the age of 61.

Nuno F.G. Loureiro, a professor at the Massachusetts Institute of Technology and a leading fusion scientist, was shot dead in December 2025. Authorities said he was killed by the same suspect involved in a shooting at Brown University. The gunman later died by suicide, and no motive was established.

Carl Grillmair, known for his work on dark matter, stellar structures and exoplanets, was shot dead at his home in February 2026. A suspect was arrested, but authorities said there was no apparent connection between the two.

The list also includes Jason Thomas, whose death followed his disappearance, as well as other individuals with varying degrees of connection to scientific research, including those working in industry or supporting roles.

How Do Authorities Explain The Differences Between Cases?

Law enforcement officials and available records show that the cases do not follow a single pattern.

Some deaths are clearly linked to criminal acts, such as shootings where suspects have been identified. Others involve missing persons where investigators have found no signs of external involvement. In certain cases, personal or medical factors have been cited.

Even in high-profile incidents such as the killing of Loureiro or Grillmair, investigators have not indicated any link to their scientific work.

What Happens Next?

The FBI has said it will examine whether any connections exist, including possible links related to access to classified information or involvement of foreign actors.

“If there’s any connections that lead to nefarious conduct or conspiracy, this FBI will make the appropriate arrest," Director Kash Patel said.

For now, the investigation remains open-ended. Federal agencies, the White House and congressional committees are all reviewing the cases, but officials have not confirmed that the incidents are connected.

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