John F. Kennedy Assassination: Ex-Secret Service agent tells his 'truth'

35th U.S. President John F. Kennedy was assassinated on 22nd November 1963 in Dallas, Texas. A former marine Lee Harvey Oswald was arrested in the case, but he was killed before trial. The Warren commission concluded that Oswald acted alone. Over the years, several conspiracy theorists have pointed at the presence of second shooter- one who is believed to have fired the fatal shot from a grassy knoll. A secret service agent who was on duty (and part of the Presidential motorcade) on the day of the tragedy, has opened up about his version of the truth. The story lends weight to the two-shooter theory. Vikram Chandra brings you a report.