Student charged with using isotope to poison 2 people

A Brown University graduate student has been accused of using a radioactive chemical to poison two other students, including a former girlfriend. Neither was harmed.

Cheng Gu, 24, placed a radioactive isotope of iodine in a dish of vegetables and chicken he gave to Yuanyuan Xiao, a fellow student in molecular pharmacology, police Lt. Stephen Campbell said Sunday.Xiao's roommate, undergraduate James O'Brien, also ate the food.

Gu was arrested Friday and charged with poisoning, assault and larceny.

The attack apparently was motivated by "some kind of love interest," said police Capt. John Ryan. Xiao told police she had been Gu's girlfriend in their native China and, for a time, in the United States.

The isotope, iodine-125, is used to diagnose and treat thyroid disorders.