Donald Trump has vowed his administration will soon have answers about reports of several American scientists and government employees who have disappeared or died in the US in recent years.
The scientists, who reportedly had access to nuclear and space information, went missing or died in several incidents over the last three years, US media outlets report. Theories have emerged online about the deaths, however there has been no evidence connecting the cases.
Speaking outside the White House on Thursday, US time, Mr Trump told reporters he had just left a meeting on the matter.
“I hope it’s random, but we’re going to know in the next week and a half,” the President said of the cases, calling it “pretty serious stuff”.
“Hopefully, I don’t know, (it’s) a coincidence, or whatever you want to call it. But some of them were very important people and we’re going to look at it.”
Asked if a foreign adversary could be behind the disappearances, Mr Trump took the opportunity to slam his predecessor, Joe Biden, saying: “Well, Biden had open borders, it wasn’t very hard to get here.”
“But we’ve got many of them out,” he added, referring to America’s immigrant population. “You know, we’ve caught many, many people.”
The President’s comments followed White House Press Secretary Karoline Leavitt’s suggestion on Wednesday that the Trump administration could investigate the matter.
“I haven’t spoken to our relevant agencies about it. I will certainly do that, and we’ll get you an answer,” she told a reporter at a briefing.
“If true, of course, that’s definitely something I think this government and administration would deem worth looking into. So let me do that for you.”
Among the missing is retired US Air Force Major General William ‘Neil’ McCasland, who was last seen at his home in Albuquerque, New Mexico, on February 27, according to the Bernalillo County Sheriff’s Office.
The 68-year-old had worked in “space research, acquisition and operations roles within the air force and the National Reconnaissance Office” while enlisted, according to the Air Force.
On the day of his disappearance, Mr McCasland’s wife, returned home from a medical appointment and her husband was nowhere to be found, Bernalillo County Sheriff John Allen said at a press conference.
His phone, prescription glasses and wearable devices were left behind at the house.
Sheriff Allen noted Ms McCasland “did state (her husband) was experiencing a mental fog” before he disappeared.
In a post on Facebook, Ms McCasland denied claims her husband had any “special knowledge about the ET bodies and debris from the Roswell crash stored at Wright-Patt”.
The Roswell crash refers to a 1947 incident during which debris was reported in New Mexico and identified by the US government as being part of a military high-altitude balloon, sparking conspiracy theories involving UFOs and extraterrestrials.
Others missing include Melissa Casias, who worked at the US Department of Energy’s Alamos National Laboratory and disappeared in June 2025, as well as Anthony Chavez, who was a retired Los Alamos National Laboratory worker and vanished in May 2025, according to The New York Post.
Jason Thomas, associate director of chemical biology at the Novartis pharmaceutical company, was also reported missing after leaving his home one night in December 2025. He was found dead last month, according to The New York Post and Fox News.
In a March 17 press release, local police said a body had been recovered from a lake in Wakefield, Massachusetts which had previously been frozen, with preliminary information suggesting it was the body of Mr Thomas.
Authorities said no foul play was suspected.
The cause of death has not been publicly disclosed.
