Background
The Committee on Oversight and Government Reform, chaired by Representative James Comer (R-KY), together with Subcommittee Chairman Eric Burlison (R-MO), addressed formal letters to four senior federal officials on 20 April 2026: Secretary of the Department of Energy Chris Wright, Secretary of the Department of War Pete Hegseth, FBI Director Kash Patel, and NASA Administrator Jared Isaacman.
The letters state that the committee is investigating "recent unconfirmed public reporting" on the disappearance and death of individuals with access to sensitive U.S. scientific information. Press reports are characterised in the letters as alleging that at least ten such individuals — described as having "a connection to U.S. nuclear secrets or rocket technology" — have "died or mysteriously vanished in recent years." The committee requested a staff-level briefing from each agency no later than 27 April 2026.
The letters also request information on "the processes and procedures in place to protect American scientific secrets and ensure personnel safety."
Named individuals
The letters name three individuals by full name and professional affiliation.
Michael David Hicks is described as a scientist at the NASA Jet Propulsion Laboratory from 1998 to 2022. The letters state that the reported pattern of deaths and disappearances "began in 2023" with his death. No cause of death is stated in the letters.
Monica Reza is described as having served as "the director of the NASA Lab's Materials Processing Group." The letters state she disappeared while hiking in California in June 2025 and remains missing.
General William Neil McCasland is described as a retired Air Force General who disappeared from his Albuquerque, New Mexico home in February 2026 with a .38 caliber revolver, and remains missing.
The letters also reference, without naming, two additional individuals affiliated with NASA JPL, two affiliated with Los Alamos National Laboratory, one MIT scientist working on nuclear fusion, one pharmaceutical researcher, and one government contractor at a nuclear weapons component production facility. These characterisations are attributed to press reporting, not to independent congressional findings.
Regarding an alleged connection between Reza and McCasland, the letters state that reports "have even alleged a direct link" between the two, characterising them as having a "close professional connection" through an Air Force-funded research programme in the early 2000s related to "advanced materials needed for reusable space vehicles and weapons." The committee does not independently assert this connection; it characterises it throughout as an allegation appearing in press reporting.
Department of War response
The DoW letter contains a notable distinction from the other three. On 16 April 2026 — four days before the formal letters were sent — Committee staff had already contacted the Department of War by email. The Department responded the same afternoon, confirming that "there are no active national security investigations of any reported missing person who was a current or a former DoW clearance holder and involved in special access programs."
The committee states in the letter that this response "leaves the Committee with many unanswered questions," and proceeds with its formal briefing request regardless.
NASA response
NASA spokesperson Bethany Stevens published a statement on 20 April 2026 via the agency's official X account (@NASASpox), posted in direct response to Press Secretary Leavitt's 17 April statement. Stevens wrote: "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."
When the fact-checking organisation PolitiFact subsequently asked NASA what projects the named individuals had worked on, the agency referred PolitiFact to Stevens' X post as its on-record response.
White House context
All four letters reference statements made by White House Press Secretary Karoline Leavitt and President Trump in mid-April 2026. On 17 April 2026, Leavitt published a formal written statement on X (@PressSec) confirming that 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." According to a report in The Hill (Juliana Manchester, 16 April 2026), Trump separately told reporters he had "just left a meeting on that subject," described it as "pretty serious stuff," and indicated he expected to have answers "in the next week and a half."
Source note
The four letters are primary source documents issued by the U.S. House of Representatives and are available via the official press release published by the Committee on Oversight and Government Reform at oversight.house.gov. The letters carry the signatures of Chairman James Comer and Subcommittee Chairman Eric Burlison and are dated 20 April 2026. The NASA statement is sourced to Bethany Stevens (@NASASpox), X post, 20 April 2026; confirmed by PolitiFact, 28 April 2026. The DoW email exchange is cited within the DoW letter itself as footnotes 9 and 10.