LOS ANGELES, CA — The remains of one of the nation's top scientists were identified this week after they were found in the wilderness next to a handgun months after she disappeared.
The development adds another layer of intrigue surrounding the recent disappearances and mysterious deaths of 10 of the nation's top scientists, most of whom worked in California. The cases have drawn scrutiny from federal officials.
New Mexico State Police this week identified human remains found in Carson National Forest as those of Melissa Casias, a 54-year-old administrative assistant at Los Alamos National Laboratory who vanished from Taos nearly a year ago, the Los Angeles Times reported.
The cause and manner of death have not yet been determined.
Casias' disappearance was one of at least 10 cases highlighted by members of Congress who have questioned whether there could be links among the deaths and disappearances of workers connected to sensitive scientific or national security work.
In April, the chairs of the House Oversight and Government Reform Committees called for briefings from federal agencies regarding the mysterious deaths and disappearances highlighted in media reports.
"These reports allege that at least ten individuals who ‘had a connection to U.S. nuclear secrets or rocket technology,’ have ‘died or mysteriously vanished in recent years.’ If the reports are accurate, these deaths and disappearances may represent a grave threat to U.S. national security and to U.S. personnel with access to scientific secrets," the lawmakers wrote.
"Public reports raise questions about a possible sinister connection between a string of mysterious deaths and disappearances, which began in 2023 with the death of Michael David Hicks, who worked as a scientist at the NASA Jet Propulsion Laboratory (JPL) from 1998 to 2022. Another JPL alum, Monica Reza, who served as the director of the NASA Lab’s Materials Processing Group, disappeared while hiking in California in June 2025 and remains missing," they added. "In February 2026 retired Air Force General William Neil McCasland disappeared from his Albuquerque, New Mexico home with a .38 caliber revolver, and remains missing. The other missing or deceased individuals, according to the reports, are two more affiliated with NASA JPL, two affiliated with Los Alamos National Laboratory, an MIT scientist working on nuclear fusion, a pharmaceutical researcher, and a government contractor working at a nuclear weapons component production facility."
Federal officials, including the FBI, have said they are reviewing the cases for any potential connections.
“The FBI is spearheading the effort to look for connections into the missing and deceased scientists. We are working with the Department of Energy, Department of War, and with our state and local law enforcement partners to find answers,” the agency said in a statement.
Several of the California-linked cases remain unresolved.
Among the California cases is the death of Caltech astrophysicist Carl Grillmair, who was shot outside his home in the Antelope Valley in February.
Los Angeles County prosecutors last week announced that Freddy Snyder, 30, pleaded not guilty to charges including murder, carjacking and residential burglary in connection with Grillmair's killing in the Antelope Valley community of Llano.
Prosecutors claim in the early morning before Grillmair's killing, Snyder armed himself with two rifles and demanded that his mother give him her car keys. When she refused, he fired a shot into the ceiling before taking off with her car.
Prosecutors claim Snyder then drove to the nearby home of Grillmair, who went outside to see the vehicle that had pulled into his driveway.
"While on his front porch, Grillmair, an astronomer at Caltech’s IPAC science and data center, was shot once in the neck and died," prosecutors said.
District Attorney Nathan Hochman described Grillmair as a "dedicated Caltech scientist" whose killing devastated his family and colleagues.
If convicted, Snyder faces a potential life sentence. A preliminary hearing was scheduled for Thursday.
READ MORE: Mysterious Deaths, Disappearances Of CA Scientists A 'Grave' National Security Concern: What To Know
Other local cases cited by media reports and federal officials include Reza, the Jet Propulsion Laboratory scientist and director of the NASA Lab’s Materials Processing Group, who disappeared while hiking in June in the Angeles National Forest. She remains missing.
Other cases — the 2023 death of JPL scientist Hicks at 59 years of age and the 2024 death of JPL researcher Frank Maiwald — have also been the subject of concern, though neither death has been publicly linked to criminal activity.
Experts have cautioned against assuming a coordinated explanation among any of the cases.
"There are a lot of people who work for national labs and universities and government research centers and some of them will go missing or commit suicide or die," University of Maryland professor Jen Golbeck previously said. "Any year you could take a bunch of those and name them as something sinister if you wanted to."
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