(Harrisburg, PA) -- Bill Cosby is going to walk out of a Pennsylvania state prison a free man. The state Supreme Court issued an opinion Wednesday to overturn his sexual assault conviction. His lawyers appealed to the court in December, arguing his trial was biased because it allowed past alleged sexual assaults to be presented. The 83-year-old Cosby has served more than two years of a three- to 10-year sentence at a state prison for the 2004 assault of Andrea Constand.