A former assistant basketball coach at a southern California high school has been charged with having sex with a 14-year-old student, officials said. The Orange County district attorney\'s office said John Tran Nguyen, 21, began an alleged sexual relationship with the girl in December while he was a contractual assistant basketball coach and she was a student at Los Amigos High School in Fountain Valley, the Los Angeles Times reported. Police learned of the alleged relationship after the girl reported to school officials he had slapped her during an argument in his car in January, the district attorney\'s office said. Nguyen is charged with one felony count of unlawful sexual intercourse and one misdemeanor count of domestic violence battery. He was freed on $20,000 bail and is scheduled to be arraigned Feb. 23. Orange County authorities said they were looking for possible additional victims and anyone with information is asked to call detective Jesse Hughes at 714­-593-4480 or district attorney investigator Lou Gutierrez at 714-347-8794.