David Xu: 5 Fast Facts You Need to Know

David Xu on LinkedIn

David Xu/LinkedIn David Xu's LinkedIn page.

David Xu is a 34-year-old Lafayette, California scientist who was arrested at his home on March 28 and is accused of poisoning his co-worker Rong Yuan. According to authorities, Xu laced Yuan’s food and water with the deadly element cadmium. While the crime was recently captured on surveillance video, it’s believed Xu has been slowly poisoning his colleague since October 2017.

Xu is charged with attempted murder and poisoning and is being held without bail. The motive for the crime is unclear and the Berkeley Police Department has stated that the case is still under investigation.

Here’s what you need to know about David Xu’s plot to poison his colleague:

1. David Xu Is a Brilliant and Well-Respected Chemical Engineer

David Xu is a talented chemical engineer with three degrees who has worked at Berkeley Engineering and Research, Inc. (BEaR) for more than 12 years. “As the senior materials engineer, I have set up a full-service materials & metallurgy laboratory at BEaR…” he wrote on the company’s website.

BEaR’s site describes Xu’s area of expertise as being in “the design and failure analysis of consumer products and industrial equipment.” Xu’s LinkedIn page says that he is “Qualified in state and federal courts as (an) expert witness. Gave over hundreds of pre-trial expert testimonies. Also consults with corporations on design and improvements.”

Xu gained wide acclaim for his work addressing the faulty bolts on the Bay Bridge, as well as investigating the Deepwater Horizon accident and the San Bruno Pipeline Explosion. Xu wrote that he was also actively researching “Lithium-Ion battery and their explosive characteristics. Cases involving electronic cigarettes, laptop batteries, phone batteries, and electric automobile batteries.”

In addition to having a flourishing career, KTVU reported that Xu is married and lives with his wife and child in Lafayette, California. Neighbor Martin Sylvia was interviewed by the news outlet, revealing that police searched Xu’s home for six to seven hours. “What on earth did his co-worker do to make him that angry?” Sylvia said.

2. Co-Worker Rong Yuan Confirmed She Was Being Poisoned by Watching Office Surveillance Footage


Berkeleyside reported that starting in 2017, Yuan repeatedly become sick after consuming food or water in her office at BEaR and grew suspicious that someone was tampering with her unattended meals and water, and described them having as a “strange taste and smell.” Yuan’s suspicions were confirmed when office security footage showed Xu putting a mysterious substance in her water on February 11 and again on March 4, 2019.

3. Yuan Family Members Were Also Poisoned

Yuan regularly fell ill after eating and sometimes required medical attention. But Yuan’s relatives also became sickened from Xu’s toxic scheme when they drank water from the same bottle Yuan had been bringing home from work. Blood samples taken from all three victims along with testing of Yuan’s water bottle all revealed traces of cadmium.

4. Cadmium Is Highly Toxic

Batteries containing cadmium

Tox Town/U.S. National Library of Medicine/National Institutes of HealthCadmium is most frequently found in batteries.

Cadmium is a silver-white metal found in the earth’s crust. It’s used in a number of different industrial products such as batteries, electroplating, and pigments. Cadmium can also be found in emissions from burning coal, oil and cigarettes as well as foods produced in cadmium-contaminated areas.

According to Occupational Safety and Health Administration (OSHA), cadmium is highly toxic and “exposure to this metal is known to cause cancer and targets the body’s cardiovascular, renal, gastrointestinal, neurological, reproductive and respiratory organs.” Symptoms of cadmium poisoning from food or drink in include stomach irritation, vomiting, and diarrhea.

Cadmium levels can be tested in the blood, urine, saliva, hair, and nails. Several treatments and decontamination procedures are recommended for anyone exposed to cadmium. It’s unknown how Xu’s victims are being treated.

5. A Plea Hearing Is Set for April 4

Xu was arraigned on April 2 but will be making his second court appearance on April 4 for a plea hearing. At the arraignment, Xu’s attorney Julia Jayne spoke with the media, where she maintained her client’s innocence. “These are allegations, only allegations,” she told reporter KTVU Henry Lee. “…When charges are brought, an individual, per our Constitutional system, is presumed innocent and that’s exactly how I intend to proceed with this case.”

When asked by reporters about a motive or possible defense strategy, she replied, “Again, you’re missing the point. That he’s presumed innocent, which all of you would like if you were accused of a crime.” At his arraignment, Xu was ordered to not have any contact with the victims.