Was the Zapruder film altered?

The most sustained alteration hypothesis was advanced by Jack White, David Lifton, and — most systematically — by John Costella and researchers associated with the 2003 symposium published as The Great Zapruder Film Hoax (ed. James Fetzer). The argument, in summary: the film in the Archives is a composite optical printing produced within days of the assassination to conceal a shot from the front and to remove the limousine's brief stop on Elm Street reported by dozens of witnesses.

The claim rests on perceived anomalies in specific frames — the "black patch" on the back of Kennedy's head in Z-317, the apparent blur in Z-302 to Z-334, and the geometry of the Stemmons Freeway sign — plus on witness testimony describing the limousine slowing nearly to a stop, a detail the film does not clearly show.

In 1996 the Assassination Records Review Board asked Roland Zavada, the retired Kodak standards director who wrote the specification for the Kodachrome II 8mm film stock Zapruder used, to examine the camera-original at the National Archives. Zavada's 1998 report runs to nearly 300 pages and remains the most technically rigorous examination of the physical film ever conducted (ARRB Final Report, Appendix H).

Zavada's key technical point: the film shows imagery in the inter-sprocket area — the strip of exposed film between the perforations — that a contact-printed or optically-duplicated 8mm forgery could not reproduce with the 1963 technology available in the two-day window the alteration theory requires.

Two decades earlier, the HSCA's Photographic Evidence Panel had already examined the film for evidence of tampering. Their 1979 conclusion: no evidence of alteration in the individual frames examined, and no discontinuity in the frame sequence (HSCA Final Report, vol. 6). The panel included optical-print specialists and motion-picture engineers drawn from the film industry.

Skeptics of the mainstream conclusion — including researchers who accept Zavada's authentication of the physical film — have raised narrower questions that remain in the peer literature:

• Whether the copies made at the Jamieson Film Company and NPIC in the 48 hours after the assassination introduce differences from the original that were never fully documented.
• Whether NPIC's second briefing board (the one Homer McMahon described to the ARRB, worked from a print that reportedly arrived via courier from Rochester) implies a chain of custody for the imagery that the official record does not capture.
• Whether witness reports of the limousine slowing more sharply than the film shows reflect perceptual error, or a real discrepancy that has never been reconciled.

These are open historical questions. They are not, on the current record, evidence that the film in the Archives is not what it claims to be.

Every formal technical examination — the FBI in 1963–64, the HSCA in 1978–79, and Kodak's Roland Zavada under ARRB commission in 1998 — has concluded that the 8mm camera-original held at the National Archives is authentic. The alteration hypothesis has not produced a technical refutation of Zavada's inter-sprocket evidence in the twenty-seven years since.

Related: Chain of custody · Where the original film is today · Sources