A chemical engineer in Berkeley, California, has released surveillance video showing her colleague allegedly poisoning her drinking water, as the man seeks to have his felony conviction cleared.
Rong Yuan, 50, began suffering symptoms including hair loss and vomiting in 2017. She was repeatedly taken to the emergency room and even travelled to China for treatment, but doctors could not identify the cause.
By 2019 she suspected her water was being tampered with. She bought a hidden camera online and installed it in her office at Berkeley Engineering and Research.
Footage from March 4, 2019, shows her colleague David Xu approaching her water bottle and pouring a substance into it. Police later determined that Xu had been adding the toxic heavy metal cadmium to her food and water for more than a year.
Laboratory tests found cadmium in the bottle at concentrations as high as 3.5 million times the U.S. federal drinking-water standard. Yuan and her parents, who had consumed water she brought home, also tested positive for elevated cadmium levels.
Xu was arrested in March 2019 and charged with attempted murder and two counts of felony poisoning. He faced a possible life sentence. Prosecutors later offered a plea deal that dropped the attempted murder charge and one poisoning count. Xu pleaded no contest to the remaining poisoning charge and was sentenced in 2024 to two years of probation, serving only one day in custody.
He completed probation in March 2026 and applied to the Alameda County Superior Court to expunge the felony conviction. Prosecutors opposed the request. A hearing was held on October 12.
Yuan, who continues to suffer health problems that prevent her from working full-time, released the 2019 footage on October 10 and spoke publicly about the case for the first time. She expressed dissatisfaction with the original sentence and concern that expungement could hide the conviction from future employers.
“This justice system has already let me down—this is my last resort,” she said.
AbdulBasit Saba is a journalist and contributor to Freelanews.com, covering news, business, and public affairs.
