President Donald Trump on Thursday
said his administration held a meeting on reports of multiple U.S. scientists who have either died or gone missing in recent months.
“I hope it’s random, but we’re going to know in the next week and a half,” he told reporters, adding that “I just left a meeting on that subject ... pretty serious stuff.”
“Some of them were very important people, and we’re going to look at it over the next short period.”
One day earlier, White House press secretary Karoline Leavitt was
asked during a press briefing about reports of 10 American scientists who have either gone missing or died since 2024, and had access to classified nuclear or aerospace material, and if the cases were being investigated as connected.
She said that she has seen the reports, but hasn't "spoken to our relevant agencies about it."
“I will certainly do that, and we'll get you an answer. If true, of course, that's definitely something I think this government administration would deem work worth looking into," Leavitt said.
As of Thursday, no federal agency has confirmed the cases are connected or that a broader coordinated investigation is underway.
The claims are based on a series of missing persons cases and deaths involving individuals with backgrounds in science, engineering, or national security, including work in aerospace, defense, and government research.
Missing Persons Cases
Monica Jacinto Reza, 60, a
materials scientist with aerospace research experience at Aerojet Rocketdyne, was reported missing on June 22, 2025, after hiking in Angeles National Forest. The Los Angeles County Sheriff’s Department said she was last seen near Angeles Crest Highway.
Melissa Casias, 53, an
administrative assistant at Los Alamos National Laboratory, was reported missing on June 26, 2025. Her phone, wallet, and other belongings were found inside her home, and her phone had been factory reset.
Casias’s niece
told The Taos News that Casias dropped her husband off at the lab, where he also worked, then returned to Taos to work from home because she forgot her employee badge. She stopped at the post office and brought her daughter lunch at a cafe in Taos Plaza.
Her daughter came home from work to find her mother missing, though Melissa’s car was still outside. Surveillance video showed Melissa leaving the John Dunn Shops in Taos, and later she was reported walking alone on Highway 518 in Talpa.
Family told The Taos News they don’t believe Casias would have left her family and that she was very close to her daughter.
Anthony Chavez, 78, a retired Los Alamos National Laboratory employee, was reported missing in 2025. Citing a family friend,
according to the Los Alamos Reporter, he was physically fit and “intellectually engaged,” and his disappearance is “out of character.”
Los Alamos National Laboratory, operated by the U.S. Department of Energy in New Mexico, is a national security research facility focused on nuclear deterrence, scientific research, and technology related to energy, defense, and global security.
William Neil McCasland, 68, a retired U.S. Air Force major general and former Air Force Research Laboratory commander, went missing on February 27, 2026. Authorities say he left home on foot, leaving his cellphone and wallet behind. His wife
said he was at some risk, but not due to dementia.
“He was not confused and disoriented,” she said. She dismissed rumors that his disappearance was linked to UFO secrets, joking on Facebook that perhaps "aliens beamed him up to the mothership," though none had been spotted over the Sandia Mountains.
Steven Garcia, 47, has been listed as missing since August 2025. Garcia worked as a property custodian at the Kansas City National Security Campus, which manufactures 80 percent of the non-nuclear components used in the nuclear stockpile.
The facility also plays an important role in the safe and secure transport of government-owned special nuclear materials, supporting the Office of Secure Transportation and the Office of Counterterrorism and Counterproliferation,
according to its website.
Deaths Cited in Reports
Nuno Loureiro, 47, a Massachusetts Institute of Technology professor specializing in fusion energy and plasma physics, was shot and killed at his home in Brookline, Massachusetts, on Dec. 15, 2025. Authorities said the suspect was Cláudio Manuel Neves Valente, a former classmate and Portuguese national. Valente also killed two students and wounded others at Brown University before dying by suicide in New Hampshire.
Carl Grillmair, 67, a California Institute of Technology astrophysicist known for discovering water on a distant planet, was fatally shot on his front porch in Llano, California, in February 2026. Grillmair’s research interests included dark matter, galactic structure, stellar populations, and exoplanets.
The suspect, Freddy Snyder, was arrested and linked to a carjacking nearby. Arraignment was delayed for Snyder, with the hearing now rescheduled for April 29,
according to Pasadena Now.
Frank Maiwald, 61, NASA Jet Propulsion Laboratory principal researcher, died July 4, 2024, in Los Angeles at age 61. Little information has been released regarding his death.
Michael David Hicks, 59, a NASA Jet Propulsion Laboratory research scientist specializing in comets and asteroids, Hicks died July 30, 2023, in California. He worked at JPL from 1998 to 2022 and contributed to major missions, including the DART, Dawn, and Deep Space 1 projects, and authored more than 80 scientific papers, according to the Division of the American Astronomical Society.
Jason Thomas, 45, a Novartis scientist from Massachusetts, was reported missing in late 2025. His body was recovered from Lake Quannapowitt in March 2026. Authorities said no foul play is suspected.
