Gerald Posner: Single Bullet, Single Gunman  [Gerald Posner is
the author of “Case Closed: Lee Harvey Oswald and the
Assassination of J.F.K.”]  THE ability to use advanced forensics
and minuscule traces of DNA to solve crimes, even cold cases
decades old, has turned many Americans into armchair sleuths
seeking to “solve” the unexpected deaths of people like Princess
Diana and Anna Nicole Smith. But sometimes, old-fashioned
evidence is as useful in solving puzzles as anything under a
nuclear microscope.  Last weekend, a never-before-seen home
movie was made public showing President John F. Kennedy’s
motorcade just before his assassination. An amateur
photographer, George Jefferies, took the footage and held onto
it for more than 40 years before casually mentioning it to his
son-in-law, who persuaded him to donate it to the Sixth Floor
Museum in Dallas. The silent 8-millimeter color film was of
interest to most people simply because it showed perhaps the
clearest close-up of Jacqueline Kennedy taken that mornin