California Woman Releases Video of Co-Worker Poisoning Her, He Seeks Expungement

A California woman has released a video showing her former co-worker, David Xu, pouring a toxic metal into her water bottle, an act that led to years of illness and frequent hospital visits. Xu, 41, is now seeking to have his felony conviction for poisoning expunged.

Rong Yuan, 50, began experiencing severe symptoms including hair loss and vomiting in January 2017, shortly after starting a job at the forensic engineering firm Berkeley Engineering and Research (BEAR). Over the next two years, her health deteriorated, leading to multiple emergency room visits. Doctors were unable to diagnose her condition, and she suspected she might have cancer.

Yuan eventually identified Xu as the perpetrator. She had suspected him after noticing a strange taste in her water and, with her mother's help, set up a spy camera at her desk. The footage captured Xu pouring a white substance, later identified by police as the toxic heavy metal cadmium, into her water bottle.

Following the discovery, Xu was arrested in March 2019 by the Berkeley Police Department and charged with attempted murder and poisoning. He was placed under house arrest with GPS monitoring. However, his case stalled in court for four years, during which he was progressively granted more freedom, including release from house arrest in November 2021 and permission to travel within the U.S. five months later.

In 2023, Pamela Price took office as Alameda County District Attorney. In 2024, Price, who became the first district attorney in the county's history to be recalled due to an increase in crime under her progressive policies, offered Xu a plea deal. He pleaded no contest to one count of poisoning and received one year of probation, a sentence significantly lighter than the potential life imprisonment he faced.

The judge overseeing the sentencing expressed surprise at the plea deal, describing it as "extremely generous." The judge doubled Xu's probation to two years. He completed the full probation sentence without serving any jail time.

Now, Xu is eligible to request the dismissal of his felony conviction under California law. If granted, the conviction would not appear on background checks, significantly impacting his future employment prospects. The court is scheduled to hear his expungement request this week.

Yuan, however, finds this prospect unacceptable. She believes Xu has not faced adequate punishment and that the California judicial system has failed her. She chose to release the spy camera footage and publicly share her story as a last resort.

An analysis by investigators confirmed that samples from Yuan's water bottle, her blood, and her parents' blood, who had also consumed water from the bottle, tested positive for cadmium. The water bottle contained 3.5 million times the federal government's safe level of cadmium for drinking water.

Long-term exposure to cadmium can lead to serious health issues, including cancer, organ damage, and bone disease, with a half-life in the human body ranging from 16 to 30 years. Symptoms of cadmium poisoning can include severe nausea, abdominal pain, vomiting, and convulsions.

Yuan stated that she continues to suffer from long-term health impacts. She also suspects that her father's death from heart failure last year may have been partly caused by his ingestion of the toxic metal.

According to court records, the district attorney's office is contesting Xu's request for dismissal. Yuan intends to testify at the upcoming expungement hearing.