Very few prosecutors would want to retry a case that is decades old. Witnesses are unavailable or memory failing. Evidence is gone, unavailable or misplaced. Without the nonsense documentaries and celebrity support and money, these vicious killers would still be in jail - they should have been hanged in the public square for the brutality of this crime. There is not a single credible alternative suspect or a single piece of credible evidence to suggest another was responsible. Period.