rarely in a murder trial do you have the kind of evidence you're about to see. a killing captured on six seconds of videotape. no one who witnessed it could believe their eyes, nor would they be able to forget it, but would the videotape send a man to prison or help him get away with murder? we warn you, some of the video you're about to see is graphic and hard to watch. a professional photographer haunted by the image he captured on camera. >> you go out and do stories and you have to wonder, is it going to happen again? >> the tragic story begins thanksgiving morning, 1992, in a little house in ft. lauderdale, florida. a 15-year-old girl named yolanda nunez commits suicide with her mother's gun. in a note she writes she's pregnant and knows if her mother found out about it, she would never approve. the suicide intensifies a deep