Poisoning Victim Releases Hidden Camera Video as Ex-Coworker Seeks to Dismiss Felony Conviction
Rong Yuan, who was poisoned with cadmium for over a year, is releasing video evidence as David Xu attempts to have his felony conviction expunged.
A former engineer convicted of poisoning a colleague at a Berkeley research laboratory is seeking to have his felony conviction dismissed, prompting the victim to release hidden-camera video that aided in his capture. David Xu, who previously worked as a senior materials engineer at Berkeley Engineering and Research, is alleged to have poisoned his colleague Rong Yuan's food and water with cadmium, a toxic heavy metal, over the course of more than a year between 2017 and 2019.
While Xu faced charges including premeditated attempted murder and two felony counts of poisoning, he accepted a plea deal for one count of poisoning and one year of probation. During Xu's sentencing in 2024, the judge extended his probation to two years, calling the initial plea deal "extremely generous." Yuan released video that appears to show Xu pouring a substance into her water bottle, as Xu prepared to ask an Alameda County judge to dismiss his felony conviction.
The district attorney's office has objected to Xu's request, but California law generally requires judges to grant such dismissals if the defendant has met the conditions of their probation. Yuan stated that releasing the hidden-camera video was her "last resort" against a legal system she believes has failed her.
Yuan recounted initial tensions with Xu when she was hired by Berkeley Engineering and Research in 2017, recalling he told her she could not use the firm's material characterization lab. She described experiencing symptoms such as dry heaving and hair loss, which intensified in July 2017 when she felt as though she was "dying" after drinking from her water bottle.
By late 2018, after repeated hospital visits, Yuan emailed Xu stating she would be working from home due to illness. Xu responded advising her to stay home and suggesting the office might be "moldy." In January 2019, after a similar incident with her water bottle, Yuan's mother tasted a sour substance, leading to suspicions of tampering. Yuan then purchased a spy camera online.
On February 11, 2019, Yuan placed the camera on her desk, and the video allegedly captured Xu accessing the area of her water bottle. A subsequent video on March 4, 2019, reportedly shows Xu pouring something into Yuan's water bottle. "My blood was frozen," Yuan said upon viewing the footage. "I almost died. I experienced death so, so close so many times. I cannot let him go."
She submitted the video evidence to the Berkeley Police Department shortly thereafter. Xu completed his probation in March. If his conviction is expunged, it would still remain part of his record. Attorneys for Xu did not immediately respond to a request for comment.