--Are you willing to sign an affidavit in federal court under penalty of perjury stating that?
--Got a third-party witness that backs up your story who is equally willing to do so?
--Do you have at least two pages worth of information about the murder: including timeframes, dates, places, other witnesses?
--Can you place me in close proximity to another proven murderer?
If you can do all those things, then your story will approach the credibility of the Jane Doe who signed this affidavit.