It’s been ten months since aerospace engineer Monica Reza mysteriously vanished while on a hike in California.
Despite weeks of Los Angeles County Sheriff’s search and rescue teams and volunteers combing the Mount Waterman trail where she was last seen, there has been no trace of the scientist – aside from one article of clothing allegedly found near the trail.
Now, Reza’s family and friends are speaking out for the first time. They told the Daily Mail they fear her June 22 disappearance could be connected to her work in advanced aerospace research.
The Daily Mail interviewed eight people – friends, relatives and other sources – familiar with Reza’s case.
Many wanted to remain anonymous and said they are also fearing for their own safety after government officials said they are looking into Reza’s disappearance.
President Donald Trump in April said his administration will launch an inquiry into Reza’s case and those of at least ten to 12 other US scientists and researchers – many with high-level clearance in defense, nuclear and aerospace fields – who also vanished mysteriously or have died.
As of April 30, Trump told media that he had been briefed on the current status of the investigation. ‘Some of them that we looked at were very sad cases, in some cases, some were sick, some left this earth self-inflicted,’ Trump said. ‘Sometimes there is a connection… So far, we’re finding that there’s not much of a connection [with these deaths].’
One of Reza’s family members told the Daily Mail that they think, regarding her disappearance, ‘The whole thing is highly suspicious.’
Monica Reza, 60, is one of about a dozen US-based scientists and officials who have either disappeared or died under mysterious circumstances. She went missing during a hike at Mount Waterman trail on June 22, 2025
Reza was hiking with two friends the day she disappeared
One of the last pictures of Reza taken during the June 22, 2025 hike
‘I know it was much more than her possibly just falling off a cliff or some random person on the trail who could’ve taken her. I had always suspected this was work-related. I know in my gut that she was abducted.’
Buzz grew on social media about the disappearance of scientists over the past three years, many of whom worked at or were affiliated with NASA’s Jet Propulsion Laboratory (JPL), like Reza, and Los Alamos National Laboratory, a secretive facility linked to classified research and UFO lore.
Those cases span a mix of confirmed deaths, unresolved missing persons reports and unrelated natural causes, but have been grouped online into a single narrative of suspicion.
Speculation has included whether there is any coordinated effort targeting individuals involved in US defense and space programs.
Friends and family said Reza was ‘very humble’ and rarely talked about her work at JPL, a federally funded research and development center located not too far from her home.
In the mid-1990s, Reza co-invented Mondaloy, a nickel-based superalloy used in rocket engines, when she worked at Rocketdyne. She also was the director of materials processing at JPL.
Reza’s Mondaloy Project was funded by the Air Force Research Laboratory and was overseen by retired Air Force General William ‘Neil’ McCasland.
Both Reza and McCasland were at one point stationed at the Wright-Patterson Air Force Base in Ohio, a site known for advanced aerospace research.
It was McCasland’s disappearance on February 27, however, that sparked growing online speculation that some of the missing or dead scientists and other individuals may have been targeted by US foreign enemies. The motivation, they thought, was an effort to hide possible classified information linked to national security or unidentified aerial phenomena.
While some people suspect foul play in these similar cases, skeptics note that tens of thousands of scientists and engineers work across these institutions – and that the loss of around a dozen scientists, however tragic, would have no tangible impact on the programs.
Between 1,200 and 1,600 people are reported missing in America’s national parks each year, while FBI data shows that more than 500,000 missing persons reports are filed annually across the US.
Still, those closest to Reza say something feels off.
Reza was known as ‘very humble’ and rarely spoke in detail about her work at NASA’s Jet Propulsion Laboratory, where she was a director of materials processing
A family friend said Reza was in ‘great spirits’ the night before she went on her hike in June.
At the time, the 60-year-old scientist had been living alone in the $1.25 million, Glassell Park, California, home she previously shared with her late husband. Our sources said he had recently died from cancer.
In the months before her disappearance, Reza had been trying to ‘get back out there again’ and rebuild her social life, according to those closest to her.
She had started taking classes at the Vedic Yoga & Meditation and Swadharma Kriya Yoga studio in Glendale.
A friend who has known the scientist for over five decades told the Daily Mail that Reza had become very close to a lot of the students and instructors, and was planning to become an instructor herself in addition to her full-time job. At the time of her disappearance, Reza was a minerals director at JPL.
She made tea for her neighbors the night before she disappeared, and told them how excited she was to go on the hike.
The Daily Mail understands Reza met with a male yoga instructor and a female friend for the hike.
Reza rode with the yoga instructor early in the morning and they started on the Mount Waterman trail around 6.30am, about 40 miles from where Reza lived.
They made it to the summit about two hours later.
The trail is a roughly six-mile hike and is considered to be a ‘moderate’ terrain in the San Gabriel Mountains that leads to an 8,041ft summit through pine and cedar forests. The popular trail, however, is usually well-maintained, clear and boasts panoramic views.
At around 8.45am, Reza and the yoga instructor began jogging down the trail, which a source told us was unusual because of the rocky terrain.
The same source said the instructor told them Reza was only a few yards behind him during their descent. The source added that along the descent, a smiling Reza stopped and posed for pictures in an open field near Double Delight Peak.
Per the re-telling, they then continued jogging down the trail with the yoga instructor about 30 yards in front of Reza.
Reza was ‘very physically fit’ said her friends, who told the Daily Mail the scientists would not have ‘taken off’ without alerting them
Volunteers searched for Reza for weeks at the Mount Waterman trail
Reza’s case is now being investigated by the LA County Sheriff’s Homicide Bureau, which has an elite unit that investigates missing person cases
Sources said that picture – taken at about 9am – would be the last anyone ever saw of her.
Reza’s case is now being investigated by the LA County Sheriff’s Homicide Bureau, which has an elite unit that investigates missing person cases.
‘The case remains an active missing person investigation,’ Sheriff’s Department officials said in a statement to the Daily Mail.
‘At this time, there are no clear indications of foul play. However, investigators are continuing to evaluate all possibilities and are not ruling anything out.’
‘All of a sudden she was just gone,’ another family member told the Daily Mail.
‘I just don’t understand that they were walking in a wide open space and then she suddenly disappears without them hearing her yell or anything. The whole thing is highly suspicious.’
The LA County Sheriff’s Department Montrose Search and Rescue team initiated the search operations in the area, along with assistance from neighboring law enforcement agencies.
They utilized aerial support, scent canines and on the ground teams to scour the trail.
They even used thermal imaging, wave-based and unmanned aerial systems but could not find any signs of Reza, according to the Sheriff’s Department.
For weeks, dozens of volunteers hiked up the same trail in the hopes of finding any clues that would lead them to Reza. One family member said the volunteers found her hat, but homicide detectives have not confirmed this discovery.
Reza’s long-time family friend said the 4-foot-11 scientist was in fit shape and was a very cautious person.
‘She is not the type to just leave without telling people and she definitely was not a suicidal person,’ another long-time friend told the Daily Mail. ‘The Search and Rescue teams are very experienced, and they had the coordinates where she was last seen.
‘It’s mostly dry brush out there, not a deep, lush forest where you wouldn’t be able to spot someone.
‘When they didn’t find her within a few days, I immediately thought, “Someone took her.” She wouldn’t have gone willingly with someone she didn’t know. This can’t be just an accident.’
A few months after Reza’s disappearance, family members packed up Reza’s belongings and placed them in storage.
The Glassell Park home – where she grew up and eventually moved back in when she married her husband – was sold in December.
Reza did not have her own children, but considered her two stepchildren like her own, another family friend said.
The Daily Mail reached Reza’s daughter-in-law, who said the family did not want to comment and referred questions to the LA County Sheriff’s Department.
The accomplished scientist was also looking forward to becoming a yoga instructor, friends told the Daily Mail
Long-time friends said Reza was grieving the death of her husband, who had recently passed away from cancer. She had a ‘very close’ relationship with her stepchildren and grandchildren
The Daily Mail spoke to the owner of the Vedic Yoga & Meditation studio. He refused to comment on Reza’s disappearance, but referred to her as ‘our dear Monica.’
He said volunteer search stopped for a few months because of recent storms, but there are plans to resume soon.
In the meantime, family members are hoping to finally get some answers.
‘Whoever did this, if it was not an accident, was a professional,’ another family member told the Daily Mail.
‘If she knew something, they could’ve easily taken her from her home. The family is obviously in shock and are just scared. They don’t know what to make of it, but Monica has a lot to live for. She would not just disappear, at least not willingly.’
In the case of McCasland, a retired Air Force general who was involved with advanced aerospace research like Reza, he seemed to have vanished from his Albuquerque home. Investigators said he left behind his prescription glasses, phone and wearable devices.
His wallet, a .38-caliber revolver, a leather holster and a red backpack were missing from his home, authorities said.
Other mysterious disappearance cases include Melissa Casias, 53, an administrative assistant at Los Alamos National Laboratory. She was last seen walking on a highway near Talpa, New Mexico on June 26, according to investigators. Her family said she left her belongings at home and her phone had been factory-reset when they found it.
Anthony Chavez, 78, a former Los Alamos National Laboratory employee, was last seen leaving his home in Los Alamos on foot on May 8.
Steven Garcia, a property custodian at the Kansas City National Security Campus in Albuquerque, went missing from his home in the same city on August 28.
Michael David Hicks and Frank Maiwald, two scientists who also worked at JPL, were widely reported to have died mysteriously in 2023 and 2024, respectively. However, according to death certificates obtained by the Daily Mail, both died of natural causes.
White House officials last week said they are coordinating with the FBI and other federal agencies to investigate the death and disappearances of the nearly dozen scientists and nuclear officials, all who have ties to NASA, JPL, Los Alamos National Laboratory and retired military personnel.
‘The White House continues to coordinate across the interagency in order to investigate these events and provide transparency to the American people,’ Principal Deputy Press Secretary Anna Kelly said in a statement to the Daily Mail. ‘We will not get ahead of the investigation.’
Family and friends started a page on social media asking for volunteers to help with search efforts, but the excursions stopped late last year because of several severe storms
