David Xu was arrested in March 2019 for poisoning his coworker Rong Yuan’s water bottle with cadmium at their workplace in Berkeley Engineering and Research (BEAR). Footage showed Xu pouring a white container’s contents into Yuan’s bottle, leading to her severe illness over two years. Samples from the bottle contained up to 3.5 million times the federal limit for drinking water of cadmium, a toxic heavy metal. Now, seven years later, Xu seeks to have his felony conviction dismissed in Alameda County Superior Court on October 12, arguing that he completed probation as required under California law. Yuan opposes this move, fearing it will allow Xu to avoid future employment scrutiny.
Written locally by qwen2.5:14b on 2026-10-12,
using this article's own text rather than the other coverage of the
same event (that is the story summary below).
Story summary
In March 2019, David Xu was arrested for poisoning his colleague Rong Yuan's water bottle with cadmium at their workplace, Berkeley Engineering and Research, located in California. Secret footage captured by Yuan showed Xu adding a toxic substance from a small white container into her bottle. Over two years prior, starting in 2017, Yuan experienced symptoms such as hair loss and vomiting that she linked to drinking from the contaminated bottle. She reported this incident to authorities, leading to Xu's arrest. Now, Xu is seeking to have charges dismissed; he will appear in Alameda County Superior Court on October 12, over seven years after the initial poisoning was recorded.
Written for “Employee Poisoning Incident” on 2026-10-12,
grounded in this article and the 0 other(s) covering the same event.
A man caught on camera poisoning his colleague’s water bottle is seeking to have charges against him dismissed, according to reports.
uncertain
charges → catch → reports
David Xu was arrested back in March 2019 after placing toxic heavy metal cadmium in his coworker Rong Yuan’s water bottle at their workplace.
asserted
Xu → arrest → workplace
Footage recorded by a secret camera set up by Yuan on her desk and shared with ABC 7 showed Xu opening a small, white container and tipping its contents into his coworker’s own bottle.
asserted
Xu → record → bottle
In the clip, recorded at Berkeley Engineering and Research, Xu quickly flees before briefly returning to adjust the position of Yuan’s water container.
asserted
Xu → record → container
Speaking to The San Francisco Standard, Yuan said that she had become increasingly ill over a two-year period, beginning in 2017.
asserted
she → speak → 2017
As her illness caused her to experience hair loss and even led to her missing work because she was vomiting, Yuan noticed that her feelings of sickness were often preceded by her drinking from her bottle.
asserted
feelings → cause → bottle
After catching Xu poisoning her water in two incidents in February and March 2019, Yuan turned the evidence over to the police.
asserted
Yuan → catch → police
“My blood was frozen,” Yuan said.
asserted
Yuan → say → ?
“I almost died.
asserted
I → die → ?
I experienced death so, so close, so many times.”
asserted
I → experience → death
Xu is set to appear in Alameda County Superior Court on October 12, over seven years after the two recorded poisonings took place.
asserted
poisonings → set → place
He had been convicted on one count of poisoning back in September 2023, after a second count of poisoning and an attempted murder charge were dropped as part of a plea deal, according to court records reviewed by The Berkeley Scanner.
uncertain
count → convict → Scanner
Xu was handed two years’ probation, which he completed in March.
asserted
he → hand → March
Now, he is set to ask an Alameda Court judge to dismiss his felony conviction, ABC 7 reports.
asserted
ABC → set → conviction
Under California law, completion of probation allows individuals to petition the court for expungement, which allows a person to withdraw a guilty or no-contest plea and to have the case dismissed.
asserted
case → allow → plea
According to The Standard, the district attorney’s office has objected to the request for dismissal.
uncertain
office → accord → dismissal
A lab report reviewed by the newspaper revealed that samples taken from Yuan’s water bottle tested positive for an immense level of cadmium - up to 3.5 million times the federal limit for drinking water.
asserted
samples → review → water
Speaking to the publication, Yuan said that she is concerned that a dismissal will result in Xu’s conviction not being visible to future employers.
asserted
conviction → speak → employers
“This legal system already failed me,” she said.
asserted
she → fail → me
The pair worked as metallurgists, with Yuan joining BEAR after Xu.
asserted
Yuan → work → Xu
A metallurgist studies the properties of metallic elements and processes them.
asserted
metallurgist → study → them
Cadmium, a heavy metal, is classified as a carcinogen and can have a toxic effect on the kidneys as well as the skeletal and respiratory systems, according to the World Health Organization.
Yuan told The Standard that, despite a tense first encounter where Xu told her that she could not use the organization’s material characterization lab, her coworker appeared concerned when she told him that she had been vomiting.
uncertain
she → classify → him
“You should work from home until you feel better.
asserted
you → work → home
No reason to rush in,” he told her.
asserted
he → rush → her
“I think BEAR is moldy (sic).”
asserted
BEAR → think → sic
The Aporia
