in what has been a riveting trial against famed comedian bill cosby, we could see a sharp turn of events. the man once known as america's dad could take the stand in a highly publicized sexual offense case. >> knowing is off the table when you're in a trial of this magnitude. you have to look at all of your options. we're weighing every option. >> even though you previously said he would not testify. >> a lot of things change. sometimes a star player plays. sometimes they don't. >> after a week of testimony from 12 witnesses the prosecution rested on friday. cosby is charged with three felony accounts of aggravated indecent assault. cnn's jean casarez has been