Rong Yuan has released hidden-camera footage that appears to show former coworker David Xu pouring a substance into her water bottle at a California laboratory. Xu pleaded no contest to a poisoning charge after prosecutors accused him of contaminating Yuan’s food and water with cadmium from 2017 to 2019. The video was made public as Xu asked an Alameda County judge to dismiss his felony conviction. Yuan said releasing it was her “last resort” after what she views as failures in the legal system.
| 1) | The poisoning allegations and criminal case |
|---|---|
| 2) | Yuan’s symptoms and growing suspicions |
| 3) | The hidden-camera footage and police report |
| 4) | The request to dismiss the felony conviction |
| 5) | Why Yuan released the video now |
The poisoning allegations and criminal case
The case involves David Xu, a former senior materials engineer at Berkeley Engineering and Research in Berkeley, California, and his former colleague Rong Yuan. Prosecutors alleged that Xu poisoned Yuan’s food and water with cadmium, a toxic heavy metal, over more than a year between 2017 and 2019. His original charges included premeditated attempted murder and two felony poisoning counts.
Xu ultimately accepted a plea agreement involving one count of poisoning and one year of probation, then pleaded no contest. At his 2024 sentencing, the judge extended probation to two years and described the agreement as “extremely generous, considering everything in this case.” The criminal proceedings centered on conduct at the Berkeley workplace and evidence later provided to police.
Yuan’s symptoms and growing suspicions
Yuan began working at Berkeley Engineering and Research in January 2017. She said her first interaction with Xu was tense after he told her she could not use the company’s material characterization laboratory. She recalled deciding to avoid overlapping with him while continuing her work.
Over the following weeks, Yuan said she experienced symptoms including dry heaving and hair loss. She described a severe episode in July 2017 after taking several sips from her water bottle, saying she felt as though she was dying. After repeated hospital visits, she emailed in November 2018 that she was vomiting and would not come to the office. Xu responded that she should work from home and suggested the building might be moldy.
Yuan reported another serious episode in January 2019 after drinking from the bottle at her desk. Her mother later tasted the water and noticed a sour flavor, which increased the family’s concern that the bottle was being tampered with.
The hidden-camera footage and police report
After the taste raised suspicions, Yuan ordered a small camera and placed it on her desk on February 11, 2019. The released footage appears to show Xu reaching toward the area where her water bottle was located at about 11:04 a.m.
A second recording, dated March 4, 2019, appears to show Xu pouring a substance into Yuan’s water bottle. Yuan said she was shocked when she watched the footage.
“My blood was frozen. I almost died. I experienced death so, so close so many times. I cannot let him go,” Yuan said.
She turned the recordings over to the Berkeley Police Department shortly afterward. The footage became part of the evidence associated with the poisoning case, although the available account does not specify the substance shown in the video itself.
The request to dismiss the felony conviction
Xu asked an Alameda County judge to dismiss his felony conviction as his probation ended. The request was scheduled for consideration on Monday, October 12, 2026. The district attorney’s office opposed the dismissal.
California law, however, requires a judge to grant such a request when a defendant has satisfied the conditions of probation. The conviction would still remain on Xu’s record if it were expunged. The available report does not state whether the judge had ruled on the request when the footage was released.
Why Yuan released the video now
Yuan made the video public as Xu pursued relief from the felony conviction. She said the decision was her last resort after concluding that the legal system had not adequately addressed what happened to her. Her stated aim was to ensure that the footage remained visible while the court considered Xu’s request.
The case has drawn attention to the evidence Yuan says documented the alleged contamination and to the legal consequences of a plea agreement that resulted in probation. Xu’s attorney was contacted for comment, but no response was included in the available account.
| Number | Key Point |
|---|---|
| 1 | Prosecutors accused Xu of poisoning Yuan with cadmium between 2017 and 2019. |
| 2 | Yuan installed a hidden camera after experiencing illness and noticing a sour taste in her water. |
| 3 | The footage appears to show Xu pouring a substance into Yuan’s bottle. |
| 4 | Xu pleaded no contest and completed probation before seeking dismissal of the felony conviction. |
Summary
The released footage is central to Yuan’s account of a prolonged poisoning allegation at a Berkeley laboratory. Xu’s plea and probation resolved the criminal case through an agreement that prosecutors opposed having dismissed. The court’s decision on the requested dismissal determines the next legal step, while the video has brought renewed public attention to Yuan’s claims.
Frequently Asked Questions
Who released the hidden-camera video?
Rong Yuan, the former coworker who said she was poisoned, released the footage.
What does the video appear to show?
The recording from March 4, 2019, appears to show David Xu pouring a substance into Yuan’s water bottle.
Why is Xu seeking dismissal of the conviction?
Xu completed the conditions of his probation and asked an Alameda County judge to dismiss the felony conviction. The district attorney’s office opposed the request.
