A UCSF fellow who allegedly tried to poison a fellow co-worker says he did it because he was stressed out, police say.
Ben Chun Liu, 38, a Chinese post-doctoral student in the United States on a work visa, was arrested Nov. 7 on charges of attempted murder and poisoning, according to the university.
Berlin said Cao first noticed there was something in her water Oct. 23. She notified police after Liu allegedly admitted he had tried to poison her.
Cao was examined at the UCSF Medical Center and later released, and is in good health now.
Berlin says the pair have worked together for at least a year and that Liu has never shown any hostility toward Cao.
The motive for the poisoning isn't known. Berlin says Liu will only say that he was stressed out.
Liu remains in custody in San Francisco on an immigration hold. Charges could be filed later today.