From a New York Times story by Peter Baker headlined “J.F.K. Assassination Witness Breaks His Silence and Raises New Questions”:

He still remembers the first gunshot. For an instant, standing on the running board of the motorcade car, he entertained the vain hope that maybe it was just a firecracker or a blown tire. But he knew guns and he knew better. Then came another shot. And another. And the president slumped down.