Postdoc Cleared on Poisoning Charges

Prosecutors have dropped all charges against Ben Chun Liu, a postdoc at the University of California at San Francisco, who was charged in October with trying to poison a co-worker, Bay City News Service reported. The case attracted considerable attention at the time of Liu's arrest, but authorities now say that there is no evidence that he was trying to poison anyone and that the substance suspected by the co-worker of being poison would only have been dangerous in massive amounts.