exact moment the shots rang out in dealey plaza. >> ladies and gentlemen, would you join me in a moment of silence in honor of the life of john fitzgerald kennedy? >> president kennedy was cut down before he could finish his first term and his story is different. he's overwhelmingly popular with americans today, much more so than when he was alive. jfk is the most popular president of the last half sentry with a 90% approval rating. i want to begin tonight with a man who stood by the kennedys on that tra gik day 50 years ago. client hill is a secret service agent who jumped on the back of the presidential limo and haunted for decades.