David Xu’s felony conviction expunged in Alameda County after poisoning case

On Monday at 9 a.m., Alameda County Superior Court Judge granted former Berkeley Engineering employee David Xu’s request to expunge the felony conviction related to his 2019 poisoning of coworker Rong Yuan.

The petition, filed in Department 109, came after Xu completed the terms of a plea deal that reduced his original charges of attempted murder and poisoning to a single count of poisoning and two years of probation. The deal, negotiated by a former prosecutor, limited Xu’s incarceration to roughly ten days in jail.

According to the Berkeley Police Department report, surveillance footage captured Xu adding cadmium, a toxic heavy metal, to Yuan’s food and water on multiple occasions over more than a year. Yuan’s health deteriorated, leading her to install a hidden camera that ultimately provided the evidence.

The probation officer recommended no jail time, noting, "The defendant is highly educated and living at home with his wife and children. He is employed and earning a stable income… The hopes of this deputy are that the defendant will take advantage of this second chance and can satisfactorily complete his probation."

The district attorney’s office objected to the expungement, arguing that the underlying conduct warranted a permanent record. However, California law requires dismissal when a defendant has fulfilled all probation conditions, a point the court emphasized in its decision.

Rong Yuan, the victim, spoke publicly for the first time after the ruling, describing her shock at the discovery and expressing confusion over Xu’s motives. She said, "I don’t know why," and highlighted the years of unexplained illness she endured before the camera revealed the poisoning.

The expungement removes the felony count from Xu’s criminal record, though the underlying incident remains part of the public record. The case has reignited discussion about plea bargaining, prosecutorial discretion, and victims’ rights in California’s criminal justice system.

The next steps involve updating Xu’s official records, while Yuan and advocacy groups continue to seek broader reforms to prevent similar incidents.