As police began their investigation into the assassination, they quickly went to the Book Depository where they found a great deal of evidence (later used by the Warren Commission). It appeared that an assassin had, in fact, fired at the President's motorcade from the sixth floor window.
The rifle was still there, "hidden" behind book boxes. Three spent shells were on the floor, near the window. A live round was still in the chamber of the high-powered rifle with its misaligned scope. And the alleged killer left tell-tale prints, including a portion of his right palmon a cardboard container, plus a latentprint on the rifle's magazine housing. (See the circled section at the bottom of Warren Commission Exhibit 629.)
Investigators interviewed 216 Dealey Plaza witnesses. Hundreds more testified in the Warren Commission hearings. Within a year, the Commission found that Lee Harvey Oswald, acting alone, had assassinated President Kennedy. Those official conclusions, however, were never universally accepted. Too many unanswered questions remained. Too many "findings" did not match the facts.
For example: What about evidence from eyewitnesses who heard shots coming from the grassy knoll area? If true, an assassin would have been in front of the President's car as well as behind it.
What about the Zapruder film which shows the effects of the fatal bullet? If the President were only shot from behind, how does one explain the movement of his head at the moment of impact? Answers, from those supporting the "lone assassin" theory, differed greatly from those with an opposite point of view. Still others believe there was a coverup of the evidence.
Scholarship continues in an effort to get to the truth. The House Select Committee on Assassinations (created as a result of continued pressure by the American people) concluded there was likely a conspiracy to kill the President. They also found "a high probability" that a second gunman fired at him, although the committee believed that Oswald fired the fatal shot.
But whether Oswald acted alone, in concert with others, or was framed does not diminish the importance of the physical evidence that was gathered in the case. And that evidence, maintained by the U.S. National Archives, allows the general public to see today what was, for decades, only available to experts and scholars.