Full Breakdown
Berkeley Engineer’s Poisoning Case Re-examined as Convicted Worker Seeks Expungement
By Drooid · · How we work
Core Event: Convicted Engineer Requests Dismissal of Felony Poisoning Conviction
David Xu, a former chemical engineer at Berkeley Engineering and Research (BEAR), will appear before an Alameda County judge to request expungement of his 2023 felony poisoning conviction. Xu pleaded no-contest to a single felony count in September 2023 and was sentenced in March 2024 to two years of probation and one day of jail time. The request follows the release of hidden-camera footage showing Xu adding a substance to colleague Rong Yuan’s water bottle.
Background & Context
Rong Yuan joined BEAR in early 2017 and soon experienced severe symptoms, including dry heaving, hair loss, vomiting, and a sour taste. After her mother detected the same sour taste from the desk water bottle, Yuan installed a spy camera in February 2019. The camera captured Xu tampering with Yuan’s bottle, leading to his arrest in March 2019 on attempted murder and poisoning charges.
Timeline
- 2017 – Yuan joins BEAR; symptoms begin.
- February 2019 – Yuan installs hidden camera; footage records Xu’s actions.
- March 4, 2019 – Video shows Xu pouring a substance into Yuan’s bottle.
- March 2019 – Xu arrested on attempted murder and poisoning charges.
- September 2023 – Xu pleads no-contest to one felony poisoning count; plea deal offered by DA Pamela Price.
- March 2026 – Xu completes probation.
- Upcoming Monday – Expungement petition to be heard at 9 a.m. in Department 109 of the Alameda County Superior Court.
Data & Statistics
- Lab analysis detected cadmium in Yuan’s water bottle at concentrations up to 3.5 million times the federal drinking-water limit.
- Xu was ordered to pay $7,058 in restitution, far below the nearly $500,000 Yuan sought.
- The plea deal reduced a potential life sentence to two years of probation and one day of jail time.
Impact: Health, Legal, and Workplace Consequences
Yuan reports lasting health effects that prevent full-time work and describes the poisoning as a “near-death” experience. The case has raised concerns about lab safety and the adequacy of penalties for chemical assaults, as well as the effect of expungement on future background checks—a outcome Yuan says would “undermine accountability.”
Official Statements & Responses
- The Alameda County District Attorney’s Office objects to Xu’s expungement request, arguing the conviction should remain on the record.
- California law requires a judge to grant expungement when a defendant has fulfilled all probation conditions, a point noted by legal analysts covering the hearing.
On-the-Ground Reports
Yuan’s account details her illness, the decision to install a camera, and the emotional impact of the footage. Her mother’s accidental consumption of the contaminated water corroborates the exposure timeline.
Conflicting Reports & Gaps
- Sources differ on the length of Xu’s probation: some cite a two-year term ending March 2026, others a “one-year” period.
- Restitution figures vary between “nearly $500,000” and “approximately $500,000,” both attributed to Yuan’s filing.
- No public comment has been obtained from Xu or his attorney.
What’s Next
The expungement hearing will decide whether Xu’s felony conviction is removed from his record. If granted, the conviction would no longer appear on standard background checks, though the conduct remains part of the public record. Yuan says she will continue to advocate for stricter penalties and greater workplace protections for laboratory personnel.