The families of some of the missing 'nuclear scientists' have lashed out over speculation that they vanished due to their jobs, telling the Daily Mail the frenzy is hindering the search for their loved ones.
Melissa Casias, 53, Anthony 'Tony' Chavez, 79, General Neil McCasland, 68, and Steven Garcia, 49, have all disappeared from their New Mexico homes within the past year.
All four had links to US defense and nuclear programs, although none are scientists: Casias worked in administration at the Los Alamos National Laboratory [LANL] and had no security clearance at all when she vanished last May, after it was yanked due to large debts racked up by her husband Mark.
Chavez and McCasland, who disappeared in May 2025 and February 2026 respectively, were both long retired and neither had had any sort of security clearance for decades.
Garcia, who vanished last August, worked for the Albuquerque outpost of the Kansas City National Security Campus and did hold low level security clearance – just enough to cover his role as a building manager.
'This Los Alamos thing, no, it had nothing to do with that,' Casias's distraught dad Joe Mondragon told the Daily Mail in an interview at his Taos, New Mexico home.
'I don't think it had anything to do with Los Alamos. Nothing at all. It was something else.'
Thomas McNally, a Phoenix-based private investigator hired by Casias's parents, angrily told the Daily Mail that the speculation is causing huge amounts of distress to her family – and could even lead to her case going unsolved.
Melissa Mondragon Casias, 53 - who has been missing since June 2025 - is one of four missing people with links to US defense and nuclear programs
The former homicide detective told the Daily Mail: 'Let me just put that [speculation] to bed real quick. Melissa and [her husband] Mark both work at LANL.
'Mark is in building construction and Melissa, although her title was an administrative assistant, that's not really what she did. She was basically a purchaser.
'They would give her a list of things to buy at Walmart and she would go out and buy them. That was her job.
'When they ran into financial trouble, they both lost their clearances and she was transferred to a position that required essentially no clearance whatsoever.
'I want to be emphatic on this point - this is in no way, shape, or form related to her job.'
Susan Wilkerson McCasland also told the Daily Mail that the speculation over her husband's disappearance is wide of the mark, answering with a categorical 'no' when asked if she believed her husband's prior security clearances and past connections with UFO researchers had anything to do with his disappearance.
In an impassioned social media post on March 6, Susan hit out at the 'misinformation' published since her husband went missing in late February and emphasized that while he did oversee a US space weapons program during his career, he had been retired and without security clearances for 13 years.
She also said his links to the UFO community via former Blink 182 frontman Tom DeLonge had long lapsed, adding that he knew the Roswell enthusiast briefly and had merely helped him out by acting as an unpaid consultant on military matters for a novel he was writing.
Speaking to the Daily Mail from his Taos, New Mexico home, Casias's distraught dad Joe Mondragon said he doesn't believe her disappearance 'had anything to do' with her job at Los Alamos
Melissa Casias and Anthony Chavez (right) were both employees at the Los Alamos National Laboratory, with Chavez retiring in 2017. Both disappeared within weeks of each other last year
Chavez, the oldest of the four missing New Mexico people, had been enjoying a quiet retirement in his modest wooden home in Los Alamos for over two decades when he went missing, with neighbors telling the Daily Mail that trying to link it to his former job amounts to a 'conspiracy theory'.
Neighbor Flora Krause, 60, told the Daily Mail: 'Tony hadn't had any sort of security clearance for 20 years. He was retired.
'He kept himself mostly to himself but we'd always see him riding his bike around the neighborhood. We've been taking care of his grass and keeping it nice for him.'
Garcia, who vanished last August, was last seen close to his Albuquerque home and had a handgun with him when he went missing.
Although the Daily Mail was unable to contact his wife Valerie, 43, a neighbor said she does not believe his disappearance had anything to do with his job and said she believes it could have something to do with his previous military career instead.
Despite their families' anguish, Casias, Garcia, McCasland, and Chavez have been included in speculation over a spate of 11 disappearances and deaths of people with ties to nuclear and national security.
The frenzy over the mystery has grown so large, it has even attracted the attention of President Trump who pledged last week to have his administration look for any foul play.
But McNally said the noise surrounding the disappearances is nothing but a distraction and has no basis in reality.
A general view of Los Alamos National Laboratory, Los Alamos, New Mexico
Retired Air Force General William Neil McCasland, 68, vanished from his New Mexico home without his phone, wearable devices or glasses on February 28
Steven Garcia, 47, was a security guard at a sensitive installation before he went missing
'I am beyond disgusted at the fact that the media is trying to tie this case to this government UFO conspiracy thing,' he told the Daily Mail.
'What the attention should be on is that there's a 53-year-old woman who's missing and has a family who love her, while the husband is out trying to date other women and doesn't care about her.'
For her dad Joe, Casias' disappearance is agony.
'We saw her on the day she went missing and she was in good spirits,' he said. 'There was nothing wrong with her at all.'
He added: 'There's someone out there who knows a little or knows a lot, if you know what I mean.
'I look up at the mountains every day and think of her. There's a lot of people who love her who want her back.'