Map Shows Last Known Location of Each Missing Scientist
Newsweek has mapped the last known locations of several missing workers with ties to advanced research, including a retired Air Force general and a NASA‑linked aerospace engineer whose disappearances have drawn congressional attention.
Among the missing are retired Air Force Major General William Neil McCasland, last seen February 27 in Albuquerque, New Mexico, and aerospace engineer Monica Reza, who disappeared in June while hiking in California.
There has been no confirmation of a concrete connection between the cases from authorities as of publication time.
Why It Matters
The House Oversight Committee has sent letters to multiple agencies requesting information about the scientists and other personnel connected to U.S. nuclear secrets or rocket technology who have died or mysteriously vanished in recent years.
President Donald Trump last week referred to the situation as “pretty serious stuff.” He said Thursday that he hoped the cases were "coincidence," but noted: "Some of them were very important people."
"Multiple equities across the Trump administration are involved in this investigation, including the FBI, DOE [Department of Energy], DOW [Department of War] and others," a White House official previously told Newsweek.
FBI director Kash Patel has confirmed his agency is investigating, with the FBI telling Newsweek it is "working with the Department of Energy, Department of War, and with our state and state and local law enforcement partners to find answers.”
NASA has also issued a statement confirming it is coordinating and cooperating with the relevant agencies.
"At this time, nothing related to NASA indicates a national security threat,” NASA spokesperson Bethany Stevens said in the statement on Monday.
What To Know
At least five disappearances have been highlighted so far.
Anthony Chavez: Former employee at Los Alamos National Laboratory
Chavez reportedly worked at the Los Alamos National Laboratory for decades before retiring in 2017.
According to authorities, the 79-year-old was last seen May 8 in Los Alamos, New Mexico. The Los Alamos Reporter said the retired research and development engineer was seen leaving his home on foot and left his keys and wallet behind.
Police said at the time that his family and friends considered his disappearance to be out of character.
Monica Reza: Director of NASA Jet Propulsion Laboratory's Materials Processing Group
Police said Reza, a resident of Los Angeles County, California, was last seen hiking on June 22, 2025, in the Mount Waterman area of the Angeles National Forest.
Reza, 60, had reportedly worked under McCasland on a government-funded aerospace project.
Melissa Casias: Administrative worker at Los Alamos National Laboratory
Casias worked in an administrative role at the lab, where she holds security clearance. She was last seen walking along a roadside in New Mexico, according to Fox News. Family members have disputed suggestions that she left of her own accord, the outlet reported.
She was 53 when she was reported missing from her home in Ranchos De Taos, New Mexico, in June 2025.
Steven Garcia: Government contractor at the Kansas City National Security Campus’ facility in Albuquerque, New Mexico
Garcia was last seen leaving his Albuquerque home on foot on August 28, 2025, and carrying a handgun. NewsNation said Garcia, 48, worked as a property custodian at the Kansas City National Security Campus, which it noted manufactures over 80 percent of the non-nuclear components for U.S. nuclear weapons.
William “Neil” McCasland: Retired U.S. Air Force Major General
As previously reported by Newsweek, McCasland held high-ranking roles in the U.S. Air Force spanning science, technology and space research, and was a commander of the Air Force Research Laboratory at Wright‑Patterson Air Force Base.
According to investigators, the 68-year-old's last known location was at or near his residence in the Quail Run Court NE area of Albuquerque on February 27, 2026.
Police said McCasland's phone, prescription glasses, and wearable devices were located at his home. Missing items included his hiking boots and a .38-caliber revolver. They added that a Silver Alert had been issued "based on information available early in the investigation that indicated Mr. McCasland could be at some level of risk and that additional public assistance was needed to locate him," though police did not release medical details.
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Reports and speculation online have also linked several deaths involving individuals connected to advanced research to a possible pattern, though authorities have not confirmed any official connection as of publication:
Amy Eskridge: Scientist reportedly researching anti-gravity technology
Died: 2022
Michael David Hicks: Research scientist at NASA's Jet Propulsion Laboratory; worked on the DART Project and Deep Space 1 mission
Died: July 2023
Frank Maiwald: Principal researcher at NASA's Jet Propulsion Laboratory
Died: July 2024
Nuno Loureiro: Director of MIT's Plasma Science and Fusion Center
Died: December 2025
Carl Grillmair: Caltech astrophysicist who worked on NASA's NEOWISE and NEO Surveyor missions.
Died: February 2026
Jason Thomas: Pharmaceutical researcher
Found dead: March 2026
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Although public attention surrounding the cases has intensified in recent weeks, some experts and people close to those who have died or gone missing have pushed back against conspiracy claims.
What Happens Next
The House Oversight Committee requested staff-level briefings from NASA, the FBI, the Defense Department, and the Department of Energy by April 27.
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This story was originally published April 22, 2026 at 7:04 AM.