The United States Federal Burau of Investigation has stepped into the centre of a sprawling, unsettling pattern involving 10 missing or deceased scientists and staff who worked at highly sensitive US nuclear and space‑technology laboratories, even as investigators and experts struggle to find any clear connection among the cases.

Senior law enforcement officials told media outlet CBS News that the bureau is now “spearheading the effort to look for connections into the missing and deceased scientists,” working alongside the Department of Energy, the Department of War, and state and local law enforcement partners to answer growing public concern.

Yet those closest to the individual investigations say the deaths and disappearances do not point to a spy‑thriller‑style conspiracy targeting the American nuclear or space programmes, but instead to a cluster of personal tragedies, accidents, and violent crimes that have collided in the public imagination via social media.

Trump flags the cases in public remarks

The national spotlight intensified last week when President Donald Trump referenced the cluster of incidents in a press‑room exchange. "I just left a meeting on that subject, so pretty serious stuff," Trump told media persons. "Hopefully, coincidence... but some of them were very important people, and we are going to look at it."

Those comments amplified an already‑heated online debate, as viral posts speculated whether a foreign power or some shadowy domestic plot could be sabotaging US scientific and defence capabilities by targeting staff at NASA's Jet Propulsion Laboratory (JPL) and Los Alamos National Laboratory.

No evidence of a coordinated pattern

Despite the fevered speculation, officials and experts involved in the probes insist there is no evidence of a coordinated plot behind the 10 cases, which span three years and involve both current and former employees at labs, plants, and support sites that together employ more than 20,000 people.

The jobs in question run from senior nuclear scientists to administrative staff, many of whom hold no special security clearances.

A spokesperson for the National Nuclear Security Administration (NNSA), the Department of Energy's nuclear‑security arm, told CBS News that the agency is aware of reports linking the cases and is "looking into the matter," but stressed that the pattern is being treated as a series of individual incidents rather than a confirmed conspiracy.

Former Energy Department officials described the apparent cluster of deaths and disappearances as “eyebrow‑raising” in the abstract but pointed out that staff and contractors at the National Laboratories are already high‑risk targets for foreign espionage, recruitment, or harassment, which makes people quick to assume a hidden hand behind sad or tragic events.

"There is no evidence of any link in these cases," one former DOE official told CBS News, adding, "People do just die—strokes, heart disease, suicide, mugging, it happens. If you attach ‘nuclear‑weapons‑facility' and some sketchy‑sounding job title, it can conceal how mundane someone's job may be."

Law‑enforcement experts say pattern is scattered

CBS News consulted several energy‑security and law‑enforcement experts, all of whom said the cases, as currently understood, do not form a convincing pattern of a coordinated campaign.

Joseph Rodgers, deputy director of the Project on Nuclear Issues at the Center for Strategic and International Studies, noted that the deaths and missing‑person cases are spread across several years and at only loosely affiliated organizations.

"If all of the scientists were working on one project or weapons system, then I would be more suspicious," Rodgers said. "As it stands, this looks like a coincidence of unfortunate events, not a targeted operation."

Scott Roecker, vice‑president for nuclear materials security at the Nuclear Threat Initiative and a former US nuclear‑security official, said the current war in Iran and the history of assassinations of Iranian nuclear scientists may be shaping public perception.

"If you were looking at a foreign adversary, Iran might come to mind because of the Iranian nuclear scientists who have been assassinated," Roecker said, adding, "But we are not like Iran. We have thousands of scientists. We have a robust infrastructure. So there would be nothing strategic Iran could achieve by taking out 10 or 20 of our nuclear scientists, as tragic as the individual deaths might be."

The 10 cases under scrutiny

Of the 10 cases that have captured online attention, one scientist disappeared while hiking in California, five died of various causes, and four people—ranging from a retired general to an administrative staffer—have gone missing in New Mexico over the past year.

Monica Jacinto Reza, 60, aerospace engineer: An engineer who worked on rocket‑engine programmes, Reza vanished on June 22, 2025, while hiking in Los Angeles County. A Facebook search group devoted to her case calls for experienced hikers to help comb the rugged terrain, but there is no publicly reported evidence tying her disappearance to espionage or any other lab‑linked incident.

Nuno Lureiro, MIT fusion physicist: MIT Professor Nuno Lureiro, a fusion and plasma‑physics expert, was shot and killed at his home in the Boston area in December by Claudio Neves Valente, a jealous former classmate. Valente had studied in the same engineering programme two decades earlier and later carried out a mass shooting at Brown University that killed two students and wounded nine others one day before killing Lureiro.

Carl Grillmair, Caltech astrophysicist: Caltech astrophysicist Carl Grillmair, who had received the NASA Exceptional Scientific Achievement Medal and multiple NASA Group Achievement Awards, was shot dead on his front porch in Los Angeles County in February. A 29‑year‑old man charged in the case had been released from prison the prior December under an "unnecessary‑prosecutions" law, according to local reports cited by CBS News.

Jason Thomas, Novartis researcher: The body of Jason Thomas, a researcher at the drugmaker Novartis, was recovered from a Massachusetts lake three months after he was reported missing. His wife told NBC News that he had been deeply distressed after the deaths of both of his parents the previous year, underscoring a personal‑tragedy narrative rather than a geopolitical one.

The most intense speculation has clustered around four disappearances in New Mexico, two of them tied to Los Alamos National Laboratory.

Retired Major General William Neil McCasland, 68: McCasland, a former commander of the Air Force Research Laboratory at Wright‑Patterson Air Force Base, was last seen at his home in Albuquerque in late February. He left without his phone, any wearable devices, or prescription glasses, carrying only hiking boots, his wallet, and a .38‑caliber revolver. Search‑and‑rescue teams led by the Bernalillo County Sheriff’s Office, aided by state and federal agencies, deployed drones and K‑9 units. A gray US Air Force sweatshirt found about a mile and a quarter east of his home was picked up by investigators on March 7, but there has been no other trace of him.

McCasland's past work and a brief association with a civilian group researching the government’s UFO files ignited online theories that he may have been taken for “secret” knowledge about extraterrestrial material at Wright‑Patterson. His wife, Susan McCasland Wilkerson, mocked those claims in a Facebook post: "Neil does not have any special knowledge about the ET bodies and debris from the Roswell crash stored at Wright‑Patt," she wrote. In jest, she added that, given the absence of any sign of him, "maybe the best hypothesis is that aliens beamed him up to the mothership," though she immediately undercut that by noting no "mothership" had been reported over the Sandia Mountains. The Bernalillo County Sheriff’s Office told CBS News that the FBI has been assisting local law enforcement in the case. "Investigators have so far uncovered no evidence of foul play," an official said, stressing that the investigation remains open‑ended and active.

Steven Garcia, 48, property custodian: Garcia, who worked as a property custodian for the National Nuclear Security Administration’s Kansas City National Security Campus in Albuquerque, vanished in August. Local and federal authorities continue to search for him, but there is no public evidence tying his disappearance to espionage or the broader pattern of cases.

Melissa Casias, 53, Los Alamos administrative assistant: Casias, a long‑time Los Alamos employee, was last seen walking alone on a highway wearing a backpack, based on surveillance footage reviewed by family. Her niece, Jazmin McMillen, said Casias was an administrative assistant without high‑level clearance and has seen no evidence linking her disappearance to the other cases, even after reviewing pages of police documents and helping organize family‑led search parties.

Anthony Chavez, 78, former Los Alamos worker: Chavez, another former Los Alamos employee, disappeared in May of last year. Local police and investigators continue to seek the public's help in finding him, but again, they have not reported any link to espionage or to the other missing‑person or death cases.

How the FBI's role is evolving

The FBI's involvement in the cluster of cases has shifted in the past week alone. On April 16, a well‑placed government source told CBS News that the bureau was not investigating the disappearances and deaths as part of a suspicious pattern; instead, the Department of Energy was leading a review of the NNSA‑linked incidents.

At the time, FBI spokesman Ben Williamson described the situation as “developing” and said the FBI was “aware and providing all assistance requested,” noting that the bureau is typically not the lead agency unless local authorities formally ask.

On Sunday, however, FBI Director Kash Patel signalled a more aggressive posture, telling Fox News that the FBI would be “spearheading the effort, collectively with our partners at the Department of Energy and the Department of War,” a shift that suggests the bureau is now centralising the information‑gathering side of the probe, even if the underlying cases remain local in nature.