US House Oversight Committee and FBI Open Probes into Deaths and Disappearances of 10 Individuals Tied to Research

The disappearances and deaths of at least 10 people tied to sensitive US research have drawn scrutiny from online sleuths. Online speculation has linked the incidents, though relatives and skeptics point to unrelated explanations.

Carl Grillmair, a 67-year-old renowned astronomer at the California Institute of Technology's IPAC science and data centre for astronomy and planetary science, was gunned down at his home in Llano, California, on 16 February. Freddy Snyder, a 29-year-old local man, has been charged with murder and burglary in the killing of Carl Grillmair. Snyder is due in court next week for his arraignment.

A man wandered onto the Grillmair property in Llano, California, with a rifle months before the killing, claiming to be coyote hunting. The man had been causing mischief at other nearby homes in Llano, California, and one resident called 911. The man returned to the Grillmair property with a baseball bat two weeks before Carl Grillmair was killed but left without causing trouble.

Louise Grillmair believes her husband Carl was targeted in a misguided revenge plot because the man blamed him for the 911 call. 'We believe [he] came for revenge, thinking Carl was the one that called 911,' says Louise Grillmair. She added, 'I think it's absolute nonsense,' about conspiracy theories regarding her husband's killing.

Carl Grillmair 'would laugh' at conspiracy theories about his killing, according to his widow Louise Grillmair. 'There's the facts, and they're out there,' says Louise Grillmair. The list of cases has 10 people, spanning fields from astronomy to administrative roles at research labs.

Science writer Mick West wrote on his Substack on 16 April that ordinary mortality over 22 months predicts approximately 4,000 deaths, 70 homicides, and 180 suicides in the US Top Secret-cleared workforce. The US Top Secret-cleared aerospace and nuclear workforce is approximately 700,000 people. West's analysis suggests no unusual pattern in the 10 cases.

William Neil McCasland, a retired United States Air Force general, disappeared from his home in New Mexico on 27 February. Susan McCasland Wilkerson called 911 three hours after returning home from a doctor's appointment to find her husband William Neil McCasland gone. She told the 911 dispatcher that William Neil McCasland had turned off his phone and left it behind but took his gun.

Susan McCasland Wilkerson noted that William Neil McCasland does not generally carry a weapon. William Neil McCasland had recently been suffering from anxiety, short-term memory loss, and lack of sleep. He had been saying 'if his brain and body keep deteriorating, he doesn't want to live like that,' according to Susan McCasland Wilkerson.

Susan McCasland Wilkerson wrote on Facebook one week after the disappearance that William Neil McCasland retired almost 13 years ago and has had only very commonly held clearances since. Eight months before McCasland's disappearance, Melissa Casias, an administrative assistant at Los Alamos National Laboratory, vanished in Taos, New Mexico.

Mark Casias wrote on Facebook in August 2025 that 'It's been the hardest six weeks of our life without you' regarding Melissa Casias. Nuno Loureiro, an MIT physicist, was murdered by a former classmate who was arrested for additional killings at Brown University. The suspect in Nuno Loureiro's murder confessed on video recordings discovered by authorities.

Another researcher vanished from his home the month after losing both parents within hours of each other. The researcher's father suffered a fatal heart attack in his arms right after his mother's death. Another scientist died of arteriosclerotic cardiovascular disease at the age of 59, according to a 2023 coroner's report.