The girl was released from the hospital Wednesday night, officials said.
Dara Cashman, the head of the sex crimes unit at the DA's office, told Bay area newspaper the Contra Costa Times that those who witnessed the alleged rape and did not report it could face aiding and abetting charges if it can be proven that their actions facilitated or goaded the perpetrators.
Earlier Cashman had indicated to ABC's KGO-TV in San Francisco it was unlikely the witnesses could be prosecuted for a crime. Public outrage, however, has risen over the witnesses' behavior.
"Maybe this crime wouldn't have been so brutal, or so prolonged if not for the audience," Eugene O'Donnell, a law professor at John Jay College of Criminal Justice and a former district attorney, told ABCNews.com. "These people were not at the aquarium looking at this through glass. They were actually standing there and creating the environment that allowed this to take place."
Given the number and nature of the way witnesses watched the rape take place, experts said, prosecutors may have a wider window than normal to charge onlookers as accessories to the crime.
"If you were on the scene and encouraging — or urging the suspect – you can be held responsible... Recording a crime is different from just watching it. Recording it can be a form of urging if the suspect feels like he's expected to perform," said O'Donnell.
ABC NEWS' Russell Goldman contributed to this report.