A hidden camera caught California engineer David Xu tampering with co-worker Rong Yuan's water, which testing later found contained the toxic heavy metal cadmium.
Yuan released the footage publicly after a judge granted Xu's request on October 12 to have his felony conviction dismissed, ABC7 Eyewitness News reported. She said she has continued to experience health problems.
The dismissal comes after Xu completed his probation in March, per the San Francisco Standard. He had originally faced charges that included premeditated attempted murder and two counts of felony poisoning, but he later accepted a plea deal and pleaded no contest to one count of poisoning.
For nearly two years, Yuan struggled with a mysterious illness while working at Berkeley Engineering and Research.
Her symptoms began in 2017 and included vomiting and hair loss. Despite seeking medical treatment, she did not initially know what was making her sick.
A breakthrough came after Yuan's mother noticed something unusual about her water. Yuan eventually set up a small camera around her desk to find out whether anyone was interfering with it.
...
Footage from February 11, 2019, captured Xu approaching her workstation and reaching toward the area where she kept her bottle. A second recording on March 4 showed him pouring a substance from a small container into the bottle.
"My blood was frozen," Yuan told the San Francisco Standard while recalling watching the footage. She immediately handed the evidence to the police.
What Investigators Found
Testing subsequently identified cadmium, a toxic heavy metal, in Yuan's water.
A sample contained cadmium at a concentration reported to be 3.5 million times the federal drinking-water limit. Yuan and her parents also tested positive for cadmium poisoning, according to ABC7.
Xu was arrested in March 2019 and charged with premeditated attempted murder and two felony counts of poisoning.
He and Yuan were both highly trained scientists working at Berkeley Engineering and Research. Xu previously worked as a materials engineer at the firm.
From a Potential Life Sentence to Probation
The criminal case stretched on for years before taking a significant turn in 2023.
Xu pleaded no contest to one felony count of poisoning in September that year under a deal prosecutors offered. He had originally faced charges carrying the possibility of life imprisonment.
At his March 2024 sentencing, the judge imposed two years of probation. The judge described the deal as "extremely generous, considering everything in this case," reports said.
Yuan, who sought nearly $500,000 in restitution, was awarded $7,058.
Xu completed his probation in March.
Judge Grants Dismissal
After completing probation, Xu asked Alameda County Superior Court to dismiss his felony conviction under California's expungement process.
Prosecutors opposed the request, but a judge granted it on October 12.
Newsweek contacted the Alameda County District Attorney's Office via email for comment on Tuesday.
The development came just as Yuan began speaking publicly about the case and releasing the footage that helped investigators uncover what was happening at her desk.
"I don't think he deserves a second chance," Yuan told ABC7 after the ruling. She also said she did not know why Xu targeted her.
Newsweek's reporters and editors used Martyn, our AI assistant, to produce this story. Learn more about Martyn here.
Contact Newsweek editors on this story: Ben Kelly and Shakeema Edwards.