Berkeley engineer arrested on charges of poisoning colleague's water

An engineer in Berkeley made his first court appearance Tuesday on charges he tried to kill a female colleague by poisoning her water with cadmium, a toxic metal.

David Xu, 34, of Lafayette on Thursday did not enter a plea to charges of premeditated attempted murder and poisoning. He is being held without bail pending his next court hearing Thursday.

Outside court, defense attorney Julia Jayne said, "These are allegations, only allegations. Charges have been filed, and i think all of you and the public knows that 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."

Xu and the alleged victim Rong Yuan, are both engineers at Berkeley Engineering and Research, or BEAR, on Gilman Street in Berkeley. 

According to court documents, the co-worker "noted a strange taste or smell from her water and food left unattended in her office." she said that happened many times over the course of more than a year.

The victim said she had to go to the hospital for emergency care. The suspect has also been charged with poisoning two of her relatives, after they got sick from drinking the water bottle she took home from work. 

Police say surveillance video from the victim's office shows the suspect adding a substance to her water bottle. Testing of the bottle and all three victims revealed the presence of cadmium, which can cause cancer and organ failure.

Pressed for any reason her client would allegedly poison his co-worker, Jayne said, "Again, you're missing the point, that he's presumed innocent, which all of you would like if you are accused of a crime."
Xu earned three degrees from UC Berkeley, including a PhD. He lives with his wife and young daughter in Lafayette, where neighbors expressed shock.

"Really surprising, because, I mean we've been waving for years," said Martin Sylvia, who lives across the street and saw Berkeley police converge on the home recently.

"They must have been in that house for a good six, seven hours, and they were searching the house for a good hour," said Sylvia, adding he was also wondering about a motive 

"What on Earth did his co-worker do to make him that angry? And what a terrible thing to do. Just a terrible thing to do."



Berkleyside reported that a fellow engineer at Berkeley Engineering and Research had noticed “a strange taste or smell from her water and food” that she had left unattended in her office, police wrote in court papers. The woman experienced “immediate and significant health problems” after consuming the food and water, and sometimes sought emergency care at the hospital, police wrote. Two of her relatives who drank from her water bottle in November and December also got sick, according to police.

Surveillance footage from the woman’s office showed Xu adding a substance to the woman’s water bottle on two occasions, Feb. 11 and March 4, police wrote. Water samples taken from the bottle on those dates “tested positive for a toxic amount of cadmium,” according to police.

Authorities also took blood samples from the woman and her relatives and found that all three “had elevated levels of cadmium,” police wrote, adding, “Exposure to cadmium can lead to organ system toxicity, cancer and/or death.”

Berkeley police told KTVU that the department is not ready to talk about the situation.

Xu also has been charged with two other counts of felony poisoning — on Nov. 29 and Dec. 13 — “which may have caused death and which did cause the infliction of great bodily injury.”

Xu has been removed from the current version of the Berkeley Engineering and Research  website. But, according to his resume, which Berkeleyside found through historical searches online, he was the principal engineer at the firm and has been trained in chemical, materials and mechanical engineering. He began his career at BEAR in 2009.

Xu received his bachelor’s, master’s and doctoral degrees at UC Berkeley.

According to an earlier version of his resume, Xu also did testing in connection with the San Bruno pipeline explosion in 2010. And at one point, Berkeleyside reported that according to a prior version of his resume, Xu was offering his services as an expert witness for depositions and trials, charging $350 an hour.