weapon, no eyewitnesses, and only one fbi agent working the case, part-time. >> deitle: my name is cynthia deitle. >> kroft: at a town hall meeting in nearby baton rouge, deitle tried to shake out some new leads and enlist journalists, activists and students to help the fbi solve the murder. why are you relying on reporters and professors? this is the most powerful law enforcement agency in the country. you have subpoena power. >> deitle: we do. we have resources that we could bring to bear on any case. >> kroft: why don't you bring them? >> deitle: they have been. but i've learned, in these cases, that a witness, a family member may be more comfortable talking to you than she would be talking to me. >> kroft: for hank allen, the time to solve his father's killing was 47 years ago. he believes the people who know what happened, black and white, would rather forget it now, and that the wall of silence and the passage of time have granted immunity to those he thinks are responsible. >> allen: here's a guy, goes on living his normal life, enjoying life. but they feel as though we're doing something