Man accused of slowly poisoning coworker

David Xu is suspected of a poisoning attempt.

This is a strange one: An engineer working at a Berkeley lab has been charged with trying to poison a co-worker by adding a toxic metal to her food and water, according to court documents.

David Xu, the principal engineer at Berkeley Engineering and Research (BEAR), where he’s worked since 2009, was arrested Thursday last week and arraigned today (April 2). In addition to one count of willful, deliberate, premeditated attempted murder, Xu was charged with felony poisoning and inflicting great bodily injury.

Xu and the victim, who was identified by court documents as Rong Yuan, were coworkers at BEAR, which  is a materials and metallurgy lab.

Yuan said became sick last year and grew suspicious when two relatives who drank from her water bottle also fell ill, according to the court documents, She told authorities that she noticed a "strange taste and smell from her water and food" that she had left unattended in her office,.

Blood samples from Yuan and two relatives who drank from her water bottle showed they all had "elevated levels of cadmium," according to Berkeley Police reports.

Surveillance footage showed Xu adding a substance to her water bottle on two different recent occasions, police said. Water samples taken from the bottle on those dates tested positive for toxic amounts of cadmium, a silver-white metal that can “lead to organ system toxicity, cancer and/or death,” according to police accounts.Cadmium is a metal found in the earth’s crust that’s primarily used in batteries, according to the National Center for Biotechnology Information.

“Eating food or drinking water with very high cadmium levels severely irritates the stomach, leading to vomiting and diarrhea, and sometimes death,” the agency wrote. Exposure to lower levels of the metal over prolonged periods can also cause kidney 

Police didn't reveal any possible motive for Xu, who remains in jail without bail.

Yuan is still recovering and declined to comment to media.

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