David Xu, a senior materials engineer at Berkeley Engineering and Research, spent two years secretly pouring cadmium — a toxic heavy metal — into his coworker's water. One sample tested at 3.5 million times the federal safety standard. On October 12, an Alameda County judge wiped his felony conviction from the record.
He got probation for poisoning. Then he got his record cleaned for completing it.
Xu's victim, an engineer named Rong Yuan, was hired at the Berkeley firm in January 2017. By January 2019, Yuan's mother noticed an odd taste and smell coming from the water her son was drinking at work. On February 11, 2019, Yuan installed a hidden camera. On March 4, 2019, it captured Xu on video pouring a substance into Yuan's water.
The original charges were premeditated attempted murder and two felony poisoning counts. What Xu actually received was a plea deal — no contest to a single poisoning count — and two years of probation. The sentencing judge called the deal "extremely generous, considering everything in this case." That's the court's own language. Extremely generous.
Yuan asked for $500,000 in restitution. He got $7,000.
Xu finished probation in March 2024, and the machinery of California's justice system did what it does next: erased the whole thing. The Alameda County District Attorney's office objected to the expungement. The judge granted it anyway.
Yuan's father died of heart failure last year. Yuan has said publicly he believes the stress of watching his son get poisoned — and then watching the system shrug — contributed. "My blood was frozen," Yuan told reporters. "I cannot let him go."
The expungement doesn't mean Xu was found innocent. It means California has decided that a man who methodically poisoned a colleague's water supply with a substance 3.5 million times above the federal safety threshold — on camera — deserves a clean slate because he showed up to his probation appointments for two years. That's the standard. Serve your probation, file the paperwork, and the felony disappears.
California's expungement statute was designed for people who committed minor offenses and turned their lives around. Xu's case involved premeditated poisoning over a two-year period. The DA opposed it. The judge had the discretion to deny it. The facts supported denial. None of that mattered.
"It's planned," Yuan said. "I don't think he deserves a second chance."
The state that can't keep its power grid running, can't keep its streets clean, and can't keep its prosecutors from plea-bargaining attempted murder down to probation has now found one more thing it can't do: keep a poisoner's felony on the books.
As reported by United Voice, the expungement was granted over the DA's explicit objection. The original charges were premeditated attempted murder. The final outcome is a man with no criminal record.
Two years of cadmium in someone's drinking water. Two years of probation. Seven thousand dollars. A clean record.
Rong Yuan is still dealing with the health consequences. David Xu is not dealing with any consequences at all.
