This is the most studied piece of film in the history of cinematography.
When the film was released publicly in 1975 many people assumed that Mrs. Kennedy jumped on the trunk after the shooting because she was frightened and trying to get out of the way. Some years later the secret service agent who jumped onto the bumper and trunk revealed that she was actually trying to retrieve a piece of the president's brain that had landed on the back of the car.
Although Abraham Zapruder made a profit from selling the film, he was so disturbed by the nightmare he had filmed that he did not keep a copy. He never owned or used another camera again.
Zapruder, always known amongst his peers as a kind man, donated the first payment from the film to the widow of Officer J.D. Tippitt, the Dallas Police Officer who was murdered shortly after and in connection with Kennedy's murder.
This is not the only film of the Kennedy assassination, but it is the only film that recorded the shooting from beginning to end.