Vietnamese police have arrested a college student who confessed to slitting her wealthy ex-boyfriend's throat with a fruit knife on Valentine's Day. Police said Vu Thi Kim Anh, 22, a fourth-year student at Hanoi Pedagogical University, confessed to murdering Nguyen Tien Chinh, 42, as the two sat in his parked Lexus. Chinh, the chief executive of a mining company, was married.