Via NYT:

A person close to Officer Wilson said that by 5 p.m. Central time, the officer had not received a call from the prosecutor’s office informing him of an indictment.

Officer Wilson’s lawyers had previously made arrangements with the prosecutor’s office planning for the possibility that he would be indicted. If the grand jury returned an indictment, Officer Wilson was expecting to receive a phone call asking him to turn himself in.

Officer Wilson was planning to voluntarily surrender if he was indicted. So far, he has not been asked to do so, the person close to him said.