A chilling hidden-camera video showing a California scientist secretly poisoning his female co-worker’s drinking water has resurfaced, exposing a disturbing workplace crime that left the victim battling serious health complications for years.
The victim, Rong Yuan, 50, a metallurgist employed at Berkeley Engineering and Research, endured severe vomiting, unexplained illnesses, hair loss and emotional distress before discovering that her colleague, David Xu, 41, had been contaminating her water with cadmium, a highly toxic heavy metal.
Laboratory examinations reportedly revealed that one water sample contained cadmium at an astonishing 3.5 million times the federal drinking-water safety limit.
Hidden Camera Exposes Disturbing Workplace Crime
Yuan’s mysterious health problems began in 2017, prompting numerous medical consultations without a clear explanation.
Her suspicions intensified after her mother noticed an unusual smell coming from her workplace water bottle.
Determined to uncover the truth, Yuan installed a hidden surveillance camera near her desk.
On March 4, 2019, the camera captured Xu approaching her workstation, opening her water bottle and pouring a substance into it before walking away.
The footage became crucial evidence in the criminal investigation.
Further testing revealed that Yuan’s parents had also experienced cadmium exposure after consuming contaminated water she had brought home.
Scientist Escapes Prison Despite Serious Charges
Xu was arrested in 2019 and initially charged with premeditated attempted murder and poisoning.
However, a 2023 plea agreement allowed him to plead no contest to one felony poisoning charge, with the remaining charges dismissed.
He subsequently received two years of probation and served no additional prison time beyond his brief initial detention.
NEW VIDEO: A hidden camera catches a California scientist poisoning his co-worker’s water bottle, leaving her with years of serious health problems and emotional distress.
Rong Yuan suffered severe vomiting, hair loss and mysterious illnesses for more than two years before discovering her water contained cadmium at levels reportedly 3.5 million times the federal limit.
David Xu was initially charged with attempted murder but received just two years of probation after pleading guilty to poisoning, while Yuan says she continues to suffer health problems and can only work part time.
Despite the severity of the crime, the lasting impact on Yuan and objections from prosecutors, a judge granted Xu’s request to expunge his felony conviction, leaving the victim questioning how he could be given a second chance while she continues to live with the consequences.
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In another controversial development, an Alameda County Superior Court judge granted his request to dismiss the felony conviction on October 12, 2026, after he completed probation.
Victim Expresses Outrage Over Court Decision
Yuan has strongly criticized the outcome, arguing that the punishment failed to reflect the suffering she experienced.
She maintains that the poisoning caused lasting physical and psychological damage, affecting her ability to work and live normally.
Her decision to release the surveillance footage has reignited public concern about workplace safety, accountability and the criminal justice system.
