The disappearances and deaths of at least 10 people tied to sensitive US research have drawn scrutiny from online sleuths and now federal investigators. But for grieving relatives, all the wild speculation is 'disgusting.' Carl Grillmair 'would laugh' at the conspiracy theories about his killing, says his widow. 'I think it's absolute nonsense,' says Louise Grillmair. 'I mean, there's the facts, and they're out there.' Her 67-year-old husband was gunned down at their Llano, California, home in February. Grillmair's alleged killer, a 29-year-old local man, Freddy Snyder, has been charged with murder and burglary and is due in court next week for his arraignment. Despite the arrest, Grillmair figures prominently in conspiracy theories about the deaths and disappearances of about 10 people with connections to top-secret labs or scientific work. They are often lumped together as 'missing scientists', but the list includes an administrative assistant, an Air Force general, an engineer and a custodian, and spans several fields, from researching exoplanets to pharmaceuticals. Online sleuths have suggested the cases may be connected, even prompting the US House of Representatives Oversight Committee and the FBI to announce investigations - despite other established explanations and family members' attempts to quell the hysteria. Grillmair's wife believes her husband was targeted in a misguided revenge plot. Months before the killing, a man had 'wandered on [their property] with a rifle', claiming to be coyote hunting. She says her husband directed the suspect to a nearby ridge. The man had also been causing mischief at other homes nearby, she says, and one resident called 911. Grillmair hadn't placed the call, but his wife believes the man blamed her husband for it as his behaviour was 'escalating'. The man came back with a baseball bat two weeks before Grillmair was killed, but left without causing anymore trouble that day, she said. Then he returned on 16 February and allegedly fatally shot Grillmair, a renowned astronomer at the California Institute of Technology's IPAC science and data centre for astronomy and planetary science. 'We believe [he] came for revenge, thinking Carl was the one that called 911,' says Louise. Sceptics have poured cold water on the wild theories surrounding the deaths. 'The US Top Secret-cleared aerospace and nuclear workforce is ~700,000 people,' science writer, investigator and pseudoscience debunker Mick West wrote on 16 April on his Substack. 'Ordinary mortality over 22 months predicts ~4,000 deaths, ~70 homicides, and ~180 suicides. The list has 10 … The deaths are real. The families' grief is real. The pattern is not.' Louise Grillmair, similarly, says that - while her husband 'would laugh' at speculation that the deaths might be connected - he would also 'probably talk statistically' to squelch conspiracies. The wife of retired Air Force General William Neil McCasland - the highest-ranking and highest-profile of the missing - took to Facebook the week after his 27 February disappearance from their New Mexico home to 'dispel some of the misinformation circulating'. Even in her 911 call, three hours after she returned home from a doctor's appointment to find her husband gone, Susan McCasland Wilkerson said she had 'some indication that he must have planned not to be found'. She told the dispatcher that he'd turned off his phone and left it behind, but took his gun, though he 'doesn't generally' carry a weapon. She also noted that her husband had recently been suffering from anxiety, short-term memory loss and lack of sleep - and he'd been 'saying if his brain and body keep deteriorating, he doesn't want to live like that'. On Facebook one week later, she wrote that, while McCasland had access during his Air Force career to 'some highly classified programs and information', he had retired 'almost 13 years ago and has had only very commonly held clearances since. It seems quite unlikely that he was taken to extract very dated secrets from him.' She also acknowledged that McCasland had acted as an unpaid consultant for Blink-182 frontman Tom DeLonge's To The Stars organisation as it sought to investigate UFOs and other matters. But her husband 'does not have any special knowledge about the ET bodies and debris from the Roswell crash stored at Wright-Patt,' Susan wrote. Eight months before McCasland's disappearance, an administrative assistant at Los Alamos National Laboratory vanished. The family of Melissa Casias also addressed the case on Facebook - again indicating that their loved one left deliberately. Their comments did little to dampen theorists' obsession with her case. 'It's been the hardest six weeks of our life without you,' her husband, Mark Casias, wrote on Facebook in August 2025.