- A woman became suspicious when she began suffering severe, recurring vomiting that often required hospital treatment
- She installed a hidden camera at her desk and captured her colleague lacing her water bottle with a substance
- A laboratory analysis on the bottle later detected traces of cadmium, a hazardous heavy metal
A California chemical engineer has walked free on probation after hidden-camera footage allegedly caught him poisoning a colleague's water bottle with a toxic heavy metal over a period spanning nearly 18 months.
Source: Twitter
David Xu, a metallurgist at Berkeley Engineering and Research, reportedly contaminated the food and drinking water of his colleague Rong Yuan using cadmium, a hazardous heavy metal.
How Poisoning Was Uncovered
Xu pleaded no contest to a single felony count of poisoning, after which a court sentenced him to two years of probation and credited him with one day served in custody.
Yuan began suffering severe, recurring vomiting that was so serious she sometimes required emergency hospital treatment.
In an email to her colleagues, she reported feeling unwell and said she needed a sick day. Xu responded by suggesting she work from home and told her there was no need to rush back to the office.
Suspicious of her worsening condition, Yuan installed a hidden camera at her workstation and captured Xu seemingly placing a substance into her water bottle.
Yuan's Fight for Justice
Laboratory analysis later detected cadmium in the bottle at concentrations up to 3.5 million times the federal limit for drinking water.
Xu was arrested on charges of attempted murder and poisoning. The attempted murder charges were eventually dropped as part of a plea agreement.
Speaking to the media, Yuan described the moment she watched the footage for the first time.
"My blood was frozen," she said. "I almost died. I experienced death so, so close so many times. I cannot let him go."
The harm extended beyond Yuan herself. Her parents were also inadvertently exposed after consuming water from the contaminated bottle.
Her mother reportedly noticed an unusual sour taste on one occasion and had also used the water to prepare food.
Yuan had sought close to $500,000 in restitution for the damage done to her and her family. The court ultimately ordered Xu to pay $7,058.
Xu completed his probation in March 2026 and is now seeking to have his felony conviction dismissed under California's expungement process, which allows eligible defendants who have fulfilled their probation to apply for a dismissal of their convictions.
Yuan, meanwhile, said she continues to deal with lasting health consequences and remains unable to work full-time.
She published a research paper documenting the long-term effects of the chemical on herself and her parents, dedicating the work to her late father, who died of heart failure.
Source: TUKO.co.ke