Gary Mack dies; called attention to JFK acoustic evidence

Gary Mack, curator of The Sixth Floor Museum in Dallasand a nationally known authority on the assassination of President John F. Kennedy, has died.

Mack made two important contributions to the JFK story.

Gary Mack, long-time curator at the Sixth Floor Museum at Dealey Plaza in Dallas stands outside of the sniper's nest on the 6th floor of the museum on Monday, February 11, 2013. Behind the glass is where Lee Harvey Oswald waited with a rifle and fired shots that killed Pres. John F. Kennedy and wounded Gov. John Connally. (David Woo/The Dallas Morning News) 03022013xBRIEFING
Gary Mack, long-time curator at the Sixth Floor Museum. . (David Woo/The Dallas Morning News)

Along with Mary Ferrell, Mack was the first to call attention to Dallas Police Department recordings made on November 22, 1963. Audio experts retained by the House Select Committee on Assassinations (HSCA) concluded that the recording contained sound impulses consistent with five shots fired in Dealey Plaza.

The National Academy of Scientists (NAS) disputed that finding, saying that the impulses cited by the HSCA had been recorded after the assassination. The NAS did not explain what caused the unique pattern of sound impulses found by the audio experts, leaving the recordings validity as evidence unresolved.

In 1991 Mack played a leading role in debunking a sensational but unfounded conspiracy theory involved a Dallas Police Department officer named Roscoe White.


12 thoughts on “Gary Mack dies; called attention to JFK acoustic evidence”

  1. Zapruders film has been retouched . Look at the back of the head near the neck. The “retouch” changes on each frame. Has this been noticed on the original film ? Has Alexandra Zapruder seen this prior to the publication of her book?

  2. Boy, I just learned about this now. Gary actually responded to my emails after asking a question on McAdam’s newsgroup. May he RIP.

  3. Gary Mack was a very good administrator and very capable historian. He understood the paranoia and the controversy that would FOREVER be generated by those who would attempt to turn the assassin’s position into a freak-show. Rest in Peace.

  4. The NAS report was a joke.

    When the Justice Department commissioned the NAS study, it was immediately apparent that it had no interest in conducting an open-minded analysis because it offered the chairmanship to none other than Luis Alvarez, a vocal defender of the Warren Commission who had staked his professional reputation on there having been no shots from the Knoll. Alvarez publicly dismissed the acoustics evidence before he even looked at it, so he wisely declined the position and instead recommended his colleague, Norman Ramsey. Nonetheless, Alvarez stayed on as the panel’s most active member. Needless to say, the conclusions of the “Ramsey Panel”, which did not include a single expert on ballistics or acoustics, were preordained. When the HSCA’s expert, Dr. Barger, met with the panel to explain and defend his work, Alverez let him know that it didn’t actually matter what he said, they were going to shoot down the HSCA’s findings regardless.

    After spending two years going over the acoustics looking for flaws, the Ramsey Panel finally issued a report which made no mention of, let alone attempt to explain, the order in the acoustic data.

    If the impulses on the dictabelt were not truly gunfire recorded by a motorcycle travelling in the Presidential motorcade, and instead represented some form of random static, then the matches to the test data could have fallen in any one of 125 different random sequences (there being 125 different ways to sequence 5 events). However, the matches did not occur in a random order. They fell 1-2-3-4-5, which is the only correct order for a microphone travelling north on Houston Street and West on Elm Street.

    Not only was the order of the matches correct, the spacing of the matching microphones was a near-perfect fit with the time between the suspect impulses on the dictabelt recording. The first three impulses were clustered together, falling approximately 1.7 and 1.1 seconds apart. This was followed by a space of 4.8 seconds before the final two impulses arrived very close together, 0.7 seconds apart. The matching microphone locations exhibited the very same pattern. The first three matches occurred at microphones that were grouped at 18 ft increments on Houston Street. There was then a 78 ft gap before the last two matches occurred at two consecutive microphones on Elm Street.

    And it wasn’t just the order and spacing that matched. The distance from the first matching microphone to the last was 143 feet and the time between the first and last suspect impulse on the tape was 8.3 seconds. In order for the motorcycle with the stuck microphone to cover 143 feet in 8.3 seconds it would need to be travelling at a speed of approximately 11.7 mph which fully corresponds with the FBI’s conclusion that the Presidential limousine was averaging 11.3 mph on Elm Street.

    Does anybody really want to believe the above is meaningless? Does it seem even remotely reasonable to suggest that some unexplained event occurred which somehow created five acoustic impulses that just happened to mimic five shots fired from two directions in the specific environment of Dealey Plaza as recorded by a microphone travelling north on Houston Street then west on Elm Street at 11 mph at 12:30 PM when the air temperature was 65 degrees F?

    That’s ludicrous.

    The dictabelt proves conspiracy and, sooner or later, folks are going to have to deal with it.

    1. It’s a shame Gerald Ford and Arlen Specter didn’t have a “change of heart” the way Mack did. I’ll never understand why Mack changed his mind from conspiracy supporter to conspiracy ridiculer. Having said that, he appeared to be a decent man, and my sympathies go to his family for his loss.

  5. Gary Mack was an outstanding gentleman.
    You could not have picked a better curator for the sixth floor museum than Gary.

    His work and his documentaries on the Kennedy Assassination
    were SUPERB..

    Gary will be so sorely missed.
    By myself and so many many others..

    I am one who has spent my whole life trying to
    find out what really happened in Dallas.
    and Gary was right there all the way
    in the fight to seek out the real truth.
    Kennedy has always been my favorite president.

    I am so deeply saddened by his passing..
    I extend my deepest sympathies to his entire family..


  6. I visited the Sixth Floor Museum on several occasions over the years and was appalled at how, under Mack’s tenure, the presentations were firmly locked into a 1964, post-Warren Report mindset. Discoveries from the HSCA investigation and ARRB disclosures were given short shrift. Foundational works of research on the assassination (e.g., Lane, Meagher, Fonzi, McKnight, Douglass & DiEugenio) were excluded entirely from the bookstore, to make way for books echoing the lone gunman myth.

    As a native of the area, who has long wished to see the Kennedy era and the President’s public execution in Dallas put into proper historical perspective, I regret to say that I have viewed the Museum as an embarrassment.

  7. I had many conversations with Gary over the years via email when I was active on John Simkin’s Spartacus JFK Forum. Gary would not post on the forums but was active by emailing when issues surrounding the museum were brought into question. He was always polite but his agenda was keeping the “lone nut” theory alive. Anything that threatened that -threatened the Museum.

    At first, I didn’t have any opinion on the Museum, good or bad, but over time I realized it was part of the establishment propaganda machine. What better way to preserve a version of events than by carefully collecting as much evidence as possible and molding it to the agenda desired?

    I noted in one of my posts the following and it resulted in a slew of emails from Gary:

    I was doing some internet research on the supposition that the South West Window on the sixth floor would be a much more logical placement for a sniper than the official placement in the South East window.

    I stumbled on a PDF on Museum’s own site that lists people who were involved with the museum’s development from the beginning through today and found an entry which I posted in my thread (and so you don’t have to refer back to my thread here it is):

    Charles A. Briggs
    The former Executive Director of the Central Intelligence Agency, Briggs spent one year working on research for The Sixth Floor project in Washington, D.C. offices of exhibition designers Bob Staples and Barbara Charles.[/quote]

    Briggs is a heavyweight. He was the number three guy in the agency for a time. Briggs’s name is all over the “Family Jewels” as released to the HSCA. Briggs authored the memo that sent Edwin P. Wilson up the river. A RIF search in either Mary Ferrell’s database or History Matters returns hundreds of documents linked to Briggs, from releases on Sylvia Odio to FOIA requests by the dozens. He was also the Acting Inspector General of the CIA for a time and maybe held the IG post itself – I’m not sure yet.

    I stated to Gary Mack that this was not insignificant but he seems to think Briggs had no significant impact on what the exhibits portray and that “I don’t know what he did, nor does that matter” because the only significant error anyone has ever found in their exhibits was the incorrect spelling of Sidney Poitier’s last name. According to him, the Museum presentations reflect “history not theory”.

    My point was not that Briggs may have made any errors, but that he was involved period. If it was so unimportant, why engage me with so many emails?

  8. I visited the Sixth Floor museum about 10 years ago, during a flight delay at DFW.
    As I strolled through the museum space, a couple from Ohio were asking a young tour guide whether the bullets could be traced to Oswald’s rifle.
    “Yes,” he told them; “through neutron activation analysis.”
    “Neutron activation analysis was a J Edgar Hoover hoax. It has been debunked and is no longer accepted in federal courts” I told the couple.
    “Who are you?”, they asked.
    “Oh, that’s Mr. Mack, the curator” said the young tour guide.
    I wonder if Gary would have similarly enlightened them…

    1. No. Mr. Mack was once considered a respected researcher by some. Since becoming curator of the Oswald did it alone Museum he had a change of heart. Why is a interesting subject discussed elsewhere. Naturally it will not be discussed by the MSM, only accolades for his work at the museum. I do not agree with his change of heart or the focus of the museum itself.
      However, it brings some people curious enough to look from behind the fence on the grassy knoll and wonder about the truth.

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