A California engineer was caught on a hidden camera poisoning his female colleague's water bottle with a highly toxic metal after she spent nearly two years suffering mysterious illnesses.
asserted
she → catch → illnesses
David Xu, a metallurgist at Berkeley Engineering and Research, chillingly suggested that maybe mold in their office might be making her sick.
But Xu secretly contaminated coworker Rong Yuan's food and drinking water with cadmium, a poisonous heavy metal capable of causing severe organ damage and even death.
uncertain
Xu → suggest → damage
The horrifying campaign unfolded between 2017 and 2019, leaving Yuan repeatedly hospitalized, vomiting uncontrollably and fearing she was dying from an undiagnosed illness.
asserted
she → unfold → illness
In a disturbing twist, Xu appeared to play the concerned colleague, even encouraging Yuan to stay home when she became too sick to work.
asserted
she → appear → Yuan
When she emailed colleagues on November 27, 2018, explaining that she was vomiting again, Xu responded: 'You should work from home until you feel better.
asserted
you → email → home
He then offered a seemingly innocent explanation for her deteriorating health: 'I think BEAR is moldy.'
asserted
BEAR → offer → health
Now, seven years after Xu's arrest, Yuan has released surveillance footage showing how she finally caught the man responsible for her suffering.
asserted
she → release → suffering
Chilling hidden-camera footage captures Berkeley engineer David Xu at the desk of colleague Rong Yuan, whose food and water he poisoned with toxic cadmium over more than a year
David Xu, 41, pleaded no contest to poisoning fellow engineer Rong Yuan after initially facing attempted murder charges.
asserted
Xu → chill → charges
He received two years of probation and credit for a day behind bars
The videos, obtained by the San Francisco Standard, were recorded using a hidden camera Yuan purchased from Amazon after becoming convinced somebody was deliberately poisoning her.
One recording, dated February 11, 2019, shows Xu approaching her desk and reaching toward the area where her water bottle was positioned.
asserted
bottle → receive → area
Another, captured on March 4, shows him pouring a substance from a small white container into her bottle before returning approximately 30 seconds later to rotate it.
asserted
him → capture → it
'My blood was frozen,' Yuan, now 50, told the Standard of watching the footage for the first time.
'I almost died.
asserted
I → freeze → time
I experienced death so, so close so many times.
asserted
I → experience → death
I cannot let him go.'
asserted
him → let → ?
The revelations have emerged as Xu, 41, prepares to ask an Alameda County judge on Monday to dismiss his felony conviction after completing a remarkably lenient sentence.
asserted
Xu → emerge → sentence
Despite initially facing charges that could have resulted in life imprisonment, Xu ultimately received just two years of probation and credit for a single day behind bars.
uncertain
Xu → face → bars
Yuan, who says she continues to suffer debilitating health problems, is furious that the man responsible could now secure a dismissal of his conviction.
uncertain
man → say → conviction
Xu is seen leaning over his colleague's desk and pouring a substance from a small white container into her water bottle in surveillance footage recorded on March 4, 2019
Yuan installed a hidden camera after suffering months of mysterious illnesses, capturing footage of Xu tampering with her drinking water that ultimately led to his arrest
'
asserted
that → see → arrest
This legal system already failed me,' she said.
asserted
she → fail → me
The nightmare began shortly after Yuan joined Berkeley Engineering and Research, a forensic engineering company, in January 2017.
asserted
Yuan → begin → January
Both scientists had earned doctorates through the University of California, Berkeley, and specialized in studying metals.
asserted
scientists → earn → metals
Yuan recalled an uncomfortable first encounter when Xu told her she could not use the company's materials characterization laboratory.
uncertain
she → recall → laboratory
'I know how to use all these tools,' she remembered telling him.
asserted
she → know → him
'I've even repaired them.
asserted
I → repair → them
'
Determined to avoid confrontation, she decided to keep her distance.
asserted
she → determine → distance
'I'll just simply do my work, and he can do whatever he wants,' she recalled thinking.
asserted
she → do → whatever
Within weeks, however, she began experiencing alarming symptoms, including hair loss and dry heaving.
asserted
she → begin → loss
By July 2017, her condition had deteriorated dramatically.
asserted
condition → deteriorate → July
After drinking from her water bottle one morning, she became desperately ill and a neighbor rushed her to the emergency room.
asserted
neighbor → drink → room
'I began to feel like I was dying,' she recalled.
asserted
she → begin → ?
Further terrifying episodes followed, prompting repeated hospital visits, consultations with specialists and even a trip to China seeking medical treatment.
asserted
episodes → follow → treatment
Yuan feared she had stomach cancer, but the medical examinations failed to explain her symptoms.
asserted
examinations → fear → symptoms
Berkeley Engineering and Research, where Xu and Yuan worked as metallurgists.
asserted
Xu → work → metallurgists
Yuan endured repeated hospital visits, severe vomiting and hair loss before discovering that her water had been deliberately contaminated
Her worried parents eventually traveled from China to help care for her.
asserted
parents → endure → her
The breakthrough came in January 2019 when her mother noticed a peculiar sour taste after drinking from Yuan's water bottle.
asserted
mother → come → bottle
Suspecting someone was tampering with her drinks, Yuan installed the hidden camera that would ultimately expose Xu.
asserted
that → suspect → Xu
Police subsequently discovered massive concentrations of cadmium in her water.
asserted
Police → discover → water
Laboratory testing revealed levels reaching 3.5 million times the federal drinking-water limit, according to a report reviewed by The Standard.
uncertain
testing → reveal → Standard
Blood samples from Yuan and both her parents also tested positive for cadmium.
asserted
samples → test → cadmium
Her mother had unknowingly used contaminated water from the bottle to prepare family meals.
asserted
mother → use → meals
Berkeley Police Sergeant Jennifer Wilson, who investigated the case, described her astonishment upon reviewing the surveillance footage.
asserted
who → investigate → footage
…and 16 more, not listed.
The Aporia
