after spending more than 20 years behind bars for a murder they say they did not commit they were given two valuable things. a potential eyewitness. a stranger had come forward to insist he saw the real killers. but could one man's claim be enough to overturn a conviction? for tommy and reese it was time to go about the past of proving it. once again, here's keith morrison with graduation night. >> the private eye and the others who joined her efforts for the highers brothers believed the newly discovered witness was telling the truth. now if they could only five the four high school friends he claimed were with him. other than when they took the trip to buy marijuana from a neighborhood drug dealer known as old man bob in 1987.