It is arguably the most infamous murder case in American history. 31 years after the OJ Simpson trial, a new investigation offers a different account of what might have happened -- the night his ex-wife Nicole Brown Simpson and her friend Ronald Goldman were stabbed to death. The murder weapon was never found and Simpson was acquitted, but he was found liable for the murders in a civil trial. Now, there is new evidence to suggest someone may have helped clean up the alleged crime. CBS News' Jericka Duncan has been looking into this.