Families Confront Speculation Amid Investigations into Scientists' Deaths and Disappearances
The deaths and disappearances of at least 10 individuals connected to sensitive US research have attracted attention from online investigators and federal authorities. However, relatives of the deceased describe the rampant speculation as "disgusting."
Carl Grillmair's widow says he would have found the conspiracy theories about his death laughable.
"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 fatally shot at their home in Llano, California, in February.
The alleged perpetrator, Freddy Snyder, 29, a local resident, has been charged with murder and burglary and is scheduled for arraignment next week.
Despite the arrest, Grillmair's case features prominently in conspiracy theories linking the deaths and disappearances of approximately 10 individuals associated with classified laboratories or scientific work.
These individuals, often collectively referred to as "missing scientists," include an administrative assistant, an Air Force general, an engineer, and a custodian. Their fields range from exoplanet research to pharmaceuticals.
Online enthusiasts have speculated about possible connections among the cases, some dating back to 2022.
The growing public interest has prompted the US House of Representatives Oversight Committee and the FBI to announce investigations into these incidents.
Former President Donald Trump commented on the matter, describing the disappearances and deaths as "pretty serious stuff," which has further fueled speculation.
However, family members emphasize that there are established explanations for their loved ones' losses and have sought to dispel the hysteria.
Grillmair's Death Attributed to Revenge Motive
Louise Grillmair believes her husband was targeted in a misguided act of revenge.
Months before the shooting, a man had trespassed on their property carrying a rifle, claiming to be hunting coyotes. Carl directed the individual to a nearby ridge.
The man had also caused disturbances at other nearby residences, leading one resident to call 911. Although Grillmair did not make the call, his wife believes the suspect blamed her husband as the situation escalated.
The man returned with a baseball bat two weeks prior to the shooting but left without incident that day.
On 16 February, the man allegedly returned and fatally shot Grillmair, a distinguished astronomer at the California Institute of Technology's IPAC science and data center for astronomy and planetary science.
"We believe [he] came for revenge, thinking Carl was the one that called 911," says Louise.
She describes her late husband as "probably the nicest guy that walked the face of the Earth."
Experts and Families Challenge Conspiracy Theories
Science writer and pseudoscience debunker Mick West wrote on 16 April on his Substack:
"The US Top Secret-cleared aerospace and nuclear workforce is ~700,000 people. 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 notes that while her husband "would laugh" at theories linking the deaths, he would also "probably talk statistically" to counter conspiracies.
Disappearance of Retired Air Force General William Neil McCasland
The wife of retired Air Force General William Neil McCasland, the most prominent of the missing, addressed misinformation on Facebook following his disappearance from their New Mexico home on 27 February.
In a 911 call made three hours after she returned from a doctor's appointment to find him missing, Susan McCasland Wilkerson indicated that he likely planned not to be found.
She informed the dispatcher that he had turned off his phone and left it behind but had taken his gun, although he "doesn't generally" carry a weapon.
She also mentioned that McCasland had recently experienced anxiety, short-term memory loss, and lack of sleep, and had expressed that if his brain and body continued to deteriorate, he did not want to live that way.
On Facebook a week later, she clarified that although McCasland had access to "some highly classified programs and information" during his Air Force career, he had retired nearly 13 years prior and held only common clearances since. She stated it was unlikely he was taken to extract outdated secrets.
She acknowledged his role as an unpaid consultant for Blink-182 frontman Tom DeLonge's To The Stars organization, which investigates UFOs and related phenomena.
However, she asserted that her husband "does not have any special knowledge about the ET bodies and debris from the Roswell crash stored at Wright-Patt."
She was referring to Wright-Patterson Air Force Base in Ohio, which UFO lore speculates may house extraterrestrial remains from debris found by a rancher in Roswell, New Mexico, in 1947.
Addressing conspiracy theories with dry humor, Susan wrote:
"At this point with absolutely no sign of him, maybe the best hypothesis is that aliens beamed him up to the mothership. However, no sightings of a mothership hovering above the Sandia Mountains have been reported."
Other Cases and Family Responses
Eight months before McCasland's disappearance, Melissa Casias, an administrative assistant at Los Alamos National Laboratory in Taos, New Mexico, vanished.
Her family also addressed the case on Facebook, indicating she left intentionally, though their statements did little to reduce theorists' focus on her disappearance.
Her husband, Mark Casias, wrote in August 2025:
"It's been the hardest six weeks of our life without you. Sierra and I are starting to worry more every day about you, we believe you are ok but can't understand why you haven't reached out."
Other cases, such as Grillmair's, have clear explanations.
MIT physicist Nuno Loureiro was murdered by a former classmate who was also arrested for additional killings at Brown University. The suspect later confessed on video recordings discovered by authorities.
Another researcher disappeared from his home the month after losing both parents within hours of each other; his father suffered a fatal heart attack in his arms shortly after his mother's death. His body was later found in a lake. His wife told US media how devastated her husband, an only child, had been following his parents' deaths.
Another scientist died of "arteriosclerotic cardiovascular disease" at age 59, according to a 2023 coroner's report.
Families Seek to Preserve Memories Amid Speculation
Louise Grillmair says conspiracy theorists have not been deterred by factual explanations. She has been contacted by many asking for her opinion.
"I said, 'Well, I can do better than an opinion,'" she says. "I have the facts."
She describes the speculation as "denigrating to their memories."
Other family members contacted by the BBC called the speculation "terrible" and "disgusting," adding to their grief, but declined to speak publicly to avoid giving the theories more attention.
For Louise Grillmair, who met her husband in an astrophysics class, she hopes the public will remember not only his scientific achievements but also his kind and generous nature.
"He helped everyone that needed help," she says. "For example, he got into two quite serious car accidents… and he didn't believe in suing. I mean, it was the other guys' fault, and he just wouldn't sue."
His obituary described Grillmair as "an avid pilot, flying small aircraft and gliders that he owned and maintained at his home; he would cheerfully accept requests to fly with him."
Friends and colleagues recall his love for the outdoors, driving tractors, and performing repairs and construction work on his house, where he maintained a small observatory with several telescopes.
His wife adds that he "had a very high standard of morals … he walked the talk."
