Despite Video Showing Berkeley Engineer Poisoning Coworker's Water, Judge Expunges His Record: Report

BERKELEY, CA — A judge on Monday agreed to expunge the case of a man convicted of poisoning his coworker in 2019 despite the latter releasing a video of the crime that has left her with lifelong health issues, according to multiple news reports.

"I don't think he deserves a second chance," Rong Yuan, whose coworker, David Xu, poisoned her with a toxic metal in 2019, told ABC7. She told the station this gave Xu a chance to hurt others.

Xu worked as a chemical engineer at Berkeley Engineering and Research when he started poisoning Yuan in 2019, according to SFGate.

Xu was originally charged with premeditated attempted murder and two counts of poisoning, according to SFGate. But a deal with prosecutors saw him plead no contest to the poisoning and, potentially, avoid major prison time, according to SFGate.

After completing probation, Xu requested his record to be cleared, according to ABC7, an act known as expungement.

But to combat his petition, Yuan released surveillance footage to ABC7 showing Xu poisoning her water bottle.

"This legal system already failed me," Yuan told SFGate. "This is my last resort."

The video apparently shows Xu tampering with her water bottle by pouring something from a white bottle into it.

Authorities say Xu poisoned Yuan with cadmium, a toxic and carcinogenic heavy metal that can cause severe chronic illness or death, according to the SFStandard.

In a research paper published by Yuan in October, she tracks the chronic health issues she's navigated since she was poisoned seven years ago.

In it, Yuan says her father and mother were also exposed to the chemical. Her father, who developed a cardiovascular cascade as a result, died of heart failure in September 2025, Yuan said.

The research paper is dedicated to him.

Read more from ABC7 and SFGate.