A former Berkeley Engineering and Research metallurgist who was convicted of poisoning a coworker with cadmium is set to ask an Alameda County Superior Court judge on Monday, Oct. 12, to dismiss his felony conviction, while the woman he poisoned has gone public with the hidden-camera videos that led to his arrest.
David Xu, 41, completed two years of probation in March. His petition, a process commonly called expungement, is scheduled for 9 a.m. in Department 109, the San Francisco Standard reported. The district attorney's office has objected, according to court records cited by the Standard, and ABC7 News reported that Xu will be in court Monday.
What happened
Rong Yuan joined the Berkeley forensic engineering firm, known as BEAR, in January 2017. Within weeks she began dry heaving and losing hair, and over the next two years she was repeatedly in the emergency room with vomiting and a persistent sour taste, the Standard reported. Suspecting her water was being tampered with, she hid a camera bought on Amazon near her desk in February 2019. A video dated March 4, 2019, shows Xu pouring a substance from a small white container into her water bottle, according to the Standard.
Berkeley police said Xu put cadmium, a toxic heavy metal, into Yuan's food and water on multiple occasions for over a year. Samples from her bottle tested at up to 3.5 million times the federal drinking water limit, according to a lab report reviewed by the Standard. Yuan's parents, who had come from China to care for her, also tested positive for cadmium.
A plea deal and probation
The DA's office charged Xu in March 2019 with premeditated attempted murder and two felony counts of poisoning. He faced up to life in prison. In September 2023, under then-District Attorney Pamela Price, he pleaded no contest to a single poisoning count with one year of probation and one day of credit for time served. At his March 2024 sentencing, Judge Kimberly Colwell called the deal "extremely generous, considering everything in this case" and doubled probation to two years, the Standard reported. Yuan sought nearly $500,000 in restitution and was awarded $7,058.
What Monday's hearing decides
Under California law, a person who completes every condition of probation is generally entitled to a dismissal, and appeals courts have held judges can deny it only for a short list of excluded crimes that does not include poisoning, according to the Standard. A dismissal would not erase the case: law enforcement would still see the arrest and conviction, it could be used if Xu is charged with a new crime, and he would have to disclose it on state license applications. Yuan's main worry is that it would no longer appear on employer background checks.
Under Marsy's Law, Yuan has a right to speak at the hearing and plans to attend. "This legal system already failed me," she told the Standard. "This is my last resort." Xu did not respond to the Standard's requests for comment.