10 people involved in assault , 19 others watched and offered no help , police say . California , Richmond , police say student was gang raped for midnight . Police posted a $ 20,000 reward Tuesday for anyone who comes to them with information that helps arrest and convict those involved in what authorities describe as a 2½-hour assault on the Richmond High School campus in suburban San Francisco . Former student , 10 , and 15-year-old arrested . Victim , 15 , remains in the hospital in stable condition .
10 people involved in assault , 19 others watched and offered no help , police say . California , Richmond , police say student was gang raped for midnight . Former student , 10 , and 15-year-old arrested . Victim , 15 , remains in the hospital in stable condition .