How the Discovery Channel Duped the American Public About the RFK Assassination Acoustics Debate

In June 2007 the Discovery Times Channel broadcast a documentary, Conspiracy Test – The RFK Assassination, which relied on unscientific practices to sensationalize their story of how a second gunman acted with Sirhan Sirhan to murder Senator Robert F. Kennedy.   The documentary challenged the  Pruszynski Tape acoustics research carried out by two teams of experts --  Philip Harrison and Professor Peter French of J P French Associates in the UK and Steve Barber, Dr Chad Zimmerman and Michael O’Dell in the US --  for my book The Forgotten Terrorist. 

J P French Associates is the United Kingdom’s longest established independent forensic speech and acoustics laboratory. The company prepares reports for the defense and prosecution in criminal cases on speaker identification, transcription, authentication and enhancement of recordings, acoustic investigation, and other related areas, including the analysis of recorded gun shots, and is regularly involved in some of the most important and high profile cases in the United Kingdom and around the world.

Philip Harrison has worked on over one thousand such cases. Harrison analyzed the Pruszynski Tape using three different methods, both independently and simultaneously. These involved (1) listening analytically to the recording via high quality headphones, (2) examining visual representations of the recording’s waveform (oscillographic displays), and (3) analyzing spectrograms (plots of sound energy across frequency over time), all using specialized computer software. Harrison’s findings were confirmed by Professor Peter French, a colleague and lecturer in forensic speech and audio analysis at the University of York. They found no more than 8 shots were present on the recording.

Both the UK and US teams had independently examined the tape then Barber and Harrison consulted with each other.
Further research carried out by these two teams after the airing of the Discovery Times Channel documentary casts serious doubt on the findings of their acoustics experts. The Discovery Times’s acoustics research was led by Philip Van Praag, electrical engineer and author of ‘Evolution of the Audio Recorder.' Wes Dooley, forensic analyst and manufacturer of ribbon microphones, was brought in to independently consider the recording. Van Praag claimed that he had identified ‘approximately 13 shot sounds’ on the Pruszynski Tape, whilst Dooley and his team located 10. Van Praag also insisted ‘certainly more than 8 shots were fired.' As Dan Moldea observed after watching the documentary, “Van Praag has concluded - and stated on national television - that thirteen shots were fired at the crime scene…… Even the kookiest kook hasn't suggested that.”

The history of how the new acoustics evidence became known to the world began, not with the Discovery Channel documentary as the producers alleged in their press release, but with Steve Barber. The Prusynzki Tape had been widely publicized in Steve Barber’s HNN article.

In early 2006 I obtained from the California State Archives an audio cassette copy of the previously unreported ‘Pruszynski Tape.' It is a tape recording containing of the sound of the gunshots in the Ambassador Hotel pantry on the night Robert Kennedy was assassinated. The recording was made by Stanislaw Pruszynski, a journalist. Pruszynski informed the Los Angeles Police Department (LAPD) that he was in the pantry at the time of the assassination. He claimed his cassette recorder was running all through the shooting. It is the only recording in existence that was taken in the pantry, and it is a record of all the shots fired from beginning to end.

In May of 2006 I asked Genevieve Troka of the California State Archives if they had facilities to make a high quality digital copy of the material which was on the cassette tape they had previously sent me. Their response was to inform me that the previous year ‘an audio expert’, Philip Van Praag, visited the California State Archives and made a digital copy of the Stanislaw Pruszynski Audio Tape. I contacted Van Praag and asked him to send a copy of his digitized version of the tape to Steve Barber who in turn forwarded the recording to Philip Harrison. Harrison and Barber had agreed to examine the tape and digitized copy for me and provide a report of their findings. After examining the digitized version of the tape Steve Barber characterized it as “…identical to the cassette in every way, except that it is much clearer.”

In April 2007 I was asked to participate in a Discover Times Channel documentary about the RFK assassination. I was informed by one of the producers that the documentary would be balanced and fair. During pre-production correspondence the producer informed me that her company, ‘Creative Differences’, had hired an independent acoustics firm to analyze the tape but refused to name the company.

The Creative Differences producer would also not release any of their experts’ findings because the company had negotiated a ‘secrecy’ agreement and their results were not allowed to be publicized until the Discovery Times program was broadcast. The producer was well aware that I had asked two teams of experts to examine the tape and their results were included in Steve Barber’s HNN article and in the galleys of my book ‘The Forgotten Terrorist’ which the Creative Differences producers obtained from my publishers. Their acoustics team was thus at an advantage in that they had access to J P French Associates’ acoustics report and also the results of the Barber, Zimmerman and O’Dell research.

During production of the Discovery Times documentary, the ‘Creative Differences’ documentary team asked that one of the experts I enlisted to examine the Pruszynski Tape, be present for interview. I asked Philip Harrison to attend. During this period they also told us their acoustics experts had identified ‘more than 8 shots on the Pruszynski Tape.' My response was to ask Creative Differences for a copy of their acoustics report for consideration before filming. However, their analysts, consisting of Van Praag, Wes Dooley and his assistant, had not even produced a written report but had simply been filmed on camera examining the recording.

Despite having grave reservations concerning the lack of any written report and also of not having the opportunity to respond to their experts’ findings, Philip Harrison and I agreed to be interviewed as we were assured the outcome would be ‘fair and balanced.' Thus, during filming, Philip was not able to respond to the Discovery Channel’s acoustics findings even though they had his report in full. 

The Discovery Channel documentary, as suspected, managed to provoke a dramatic media and internet response, in the main because the producers had sensationalized everything about the RFK case. Furthermore, the documentary makers skewed everything in favour of conspiracy as I suspected after first reading the press release which, as I previously mentioned, had wrongly attributed the tape’s revelation to themselves when in fact Steve Barber was the first to publicize it worldwide in an article for the History News Network.

Discovery Times was also remiss in not telling its viewers the whole story about the acoustics research carried out for me. I had told their producers there had been twoteams of experts (Harrison/French and Barber/Zimmerman/O’Dell) looking at the Pruszynski Tape with a view to publishing the findings in my book The Forgotten Terrorist. I named all the contributors to the research. This fact appears to have been lost on the producers.

Contrary to the inferences made by the Discovery Times’s documentary, we have, in reality, three experts in the United States --  Philip van Praag, Wes Dooley and his assistant, Paul Pragus and one expert in Denmark, Eddie Brixen  --  who examined the tape and who concluded there were 10 or 13 shots fired. But we have five experts* in the US and UK who found no more than the acoustic signatures of 8 shots fired.  Philip Harrison provided a written report of his findings. Harrison’s work was confirmed by forensic speech and acoustics expert Professor Peter French of J P French Associates and York University. Steve Barber was interviewed for my book and his comments about his team’s research is included within the narrative of my book. The Discovery Times Channel teams have produced no written report nor have they published their findings in any book or journal. It should be quite obvious to every person in the scientific community that Van Praag’s and Wes Dooley’s findings should never have been characterized by Discovery Times’s producers as scientific fact without publication of their research for peer review. As Harrison observed, “The only way in which to fully assess and respond to what they are saying is for them to prepare a comprehensive written report and provide us with copies of all the materials on which they've relied. This is the way that science is done.”

Had the documentary producers insisted on having their acoustics team’s results examined by J P French Associates and Steve Barber’s team they would have discovered the many flaws in the acoustics evidence presented by their experts.

Following the airing of the documentary Harrison and Barber decided to look at the acoustics evidence again and found a number of problems with the presented analyses:

*The program claimed that the fourth expert, Philip Harrison, wasn't using the best quality recordings and that he didn't take into account the position of the Polish journalist doing the recording. The Discovery Times narrator added, “Harrison was working from a single copy of Van Praag's recording from the California State Archives. Not from Van Praag's masters. Harrison was also not aware of the details surrounding the events of that night at the Ambassador. Most importantly, he did not know the location of Pruszynski's microphone and how it was moving when the shots were fired.” He also later claims that “with these important differences it's no surprise that Wes Dooley and Paul Pragus as well as their colleague in Denmark found more shots." These statements are misleading. It is clearly stated in the documentary that Eddie Brixen had only been provided with a single copy of the recording and there is no indication that he was given information about Pruszynski’s movements. So the relevance of this information, which was claimed to be “critical to an accurate analysis of the recording”, seems somewhat less significant as Brixen also appeared to locate more than 8 shots.

* Philip Harrison had been working initially from the CSA cassette tape and then Van Praag’s digitized version. Van Praag had this to say about the copy of the digitized version sent to Steve Barber who in turn forwarded it to Philip Harrison: “The copy I made for you …….. I did not apply any filtering to the recording you obtained from me. The transcription I made utilized the FINEST studio professional console analog equipment for playback (quite necessary), along with multiple digital and analog machines on the record side.”As Steve Barber noted, “Van Praag said that he sent us the digital copy from his archives, which came from the same CSA source that we got our cassette copy from and confirmed to me that he didn't do ‘any type of filtering.'" Digitized copies lose nothing in the transaction. As Michael O’Dell observed, “The bit about Ayton's expert (in the documentary) was spin by the narrator……none of this analysis would be changed by having the master copy.” Furthermore, Harrison has taken issue with the degree of importance attached to Van Praag’s multiple copies of the Pruszynski Tape. Harrison stated, “Since he only played back the recording once the numerous versions will have limited value for the analysis.”

*Harrison and Barber were obviously interested in the new, albeit limited, information available from the documentary and were intrigued as to the details of Van Praag’s work that had resulted in such different findings. Therefore, Harrison and Barber contacted Van Praag but he was not willing to discuss his findings in detail. Harrison then contacted Wes Dooley. According to Harrison, “Dooley revealed some interesting information including the fact they had to destroy all their files after the filming findings and that Dooley didn’t seem to consider his findings to be as conclusive as the documentary might have made out."

*Van Praag did admit to Steve Barber that Creative Differences had produced their own audio level graph with 13 numbers ‘popping up’ and Van Praag had no idea who constructed it. Van Praag said it ‘in no way’ necessarily represented what his findings revealed and that the documentary makers had stooped to a low level in presenting his findings. So if Creative Differences misunderstood Van Praag’s research (even though he did say 13 shots had been identified) it is not a great leap of the imagination to assume their interpretation of Van Praag’s work shown in the documentary was erroneous. Another of Van Praag’s comments to Steve Barber following the broadcast of the Discovery Times documentary (“Until I finish sorting it [my analysis] out …..a day, a week, a month…”) is also revelatory. Van Praag thus presented his findings to Discovery viewers when, by his own admission, he had not completed his research.

*Discovery’s acoustics ‘experts’ arrived at their number of gunshots fired, not by an examination of the Pruszynski Tape alone, but by also considering the location of Pruszynski and his microphone at the time of the shots. The location information appeared to be derived by synching a thump sound on news broadcast footage with the same sound on the Pruszynski Tape. According to the documentary Pruszynski was said to have walked behind the podium when RFK and his retinue left the Embassy stageand down the steps to the right of the stage (viewed from the front) and is last seen approaching the stage door that leads back in the direction of the pantry. Van Praag’s description was that Pruszynski is seen “walking down the stairs and at this point we hear a thump just as he’s beginning to enter the kitchen pantry area and we know from Pruszynski’s recording that that is the point where the shots are fired."

Steve Barber and Philip Harrison were able to locate the thump, which was played several times on the documentary, on a section of news footage obtained from the California State Archives. However, this material is in color and is not the black and white footage in which Pruszynski can be seen in the documentary. It therefore must be assumed that Van Praag had synchronised the images of the color footage with those of the black and white footage and the thump sound to obtain Pruszynski’s location at the time of the shots. Barber and Harrison then attempted to locate the thump sound on the Pruszynski recording. Despite there being a few candidate impulse sounds none were similar enough to the news footage thump for them to be able to accurately determine which sound Van Praag considered to be the thump.

In view of their serious doubts over Van Praag’s synchronisation Barber and Harrison contacted him again to try to obtain confirmation that the ‘thump’ that was played during the documentary was the same one he had used. However, he was not prepared to enter into correspondence on the subject. Van Praag’s description of the timing of events indicate that the thump occurs very shortly before the shots. This raises further issues in relation to the images seen on the color TV footage. There are over 8 seconds of material after the thump before there is a break in the recording.  During those 8 seconds there are no indications of panic within the ballroom crowd and no shot sounds can be heard. There is a further short recording with a duration of 6 seconds and again there are no obvious signs of panic in the crowd. It isn’t until the next recording, some 14 seconds after the thump (not including time elapsed whilst the camera was not recording) that signs of panic start to become apparent. If Van Praag’s timings are correct then why did it take so long for the crowd to react?

*Van Praag’s 13 shot scenario is based on a compilation of various sounds on the tapes which on first examination appear to be gunshots. Steve Barber is convinced Van Praag was confusing ‘thump’ sounds with gunshots i.e. the two sounds identified as  ‘thumps’ in his HNN article; the string of 8 shots; plus the sound between shots 3 and 4; and this brings the total to 11. Furthermore, as one of the thumps rises in pitch it is extremely unlikely it was the sound of a gunshot. Close inspection of one of the plots produced by Eddie Brixen, which is shown in the documentary, appears to show that he is only convinced of 8 shots. Other features are marked including two that are labelled ‘probably a shot.' This shows that there isn’t even a consensus between those who believe that the recording contains more than 8 shots. One of Wes Dooley’s closing remarks is that the recording ‘merits closer examination.'

*In addition to the issue concerning the number of total shots fired, the show also said at least two of the shots on the tape were fired too closely to have come from the same gun. They even go to a firing range where a firearms expert conducts experiments using the same type of gun as Sirhan. These show that it would not be possible to fire two shots from that gun in the time required by the recording. This is presented as corroborating evidence for a second gunman when the crucial point is completely ignored -- what is the actual evidence for the second sound being a shot?

Having highlighted serious concerns about the reliability and usefulness of both the location information and Van Praag’s extra copies of the recording, it is clear that the bottom line is that the differences between the findings of the analysts is simply a matter of interpretation. All of the analysts involved would agree that there are more than 8 impulse sounds in the Pruszynski recording in the area of the shots. (Impulse sounds are characterized by a sharp onset and rapid decay. They are caused by a wide range of events, for example a gun being fired, a balloon bursting, a firecracker being let off or one object hitting another.) There are, in fact, many other impulse sounds throughout the entire recording and to simply attribute other impulse sounds in the region of the shots to a second gunman without being able to provide a reasoned scientific argument is reckless.

The documentary provides no information about why Van Praag considers the location of Pruszynski to be so important or how it accounts for the differences between the analysts’ findings. The same is true for Van Praag’s different recordings. More importantly no explanation is given for why the documentary’s experts discount all other possible sources for the impulse sounds and instead conclude that they are gunshots.

H. L. Mencken once ridiculed "the virulence of the national appetite for bogus revelation." These truths seem to be more prevalent now in the internet age and in the public’s appetite for television sensationalism. The danger in well-presented documentaries of this kind and their dissemination throughout the internet is that they provide the only historical information source for the majority of Americans, especially the youth of America. As RFK assassination expert, Dan Moldea, stated, “  ……  I thought that this program was very exciting and well done, just as I thought that Oliver Stone's JFK was very exciting and well done.  The problem is that both presentations defy belief.  In other words, good dramas, terrible history.” 

There is also an additional danger – although Van Praag’s and Wes Dooley’s findings will be rejected by the scientific community on the basis they have not provided a written report for consideration by their peers, they have unwittingly (or consciously) provided scientifically unsupported results to conspiracists who have their own agenda in promoting an unproven conspiracy to murder Robert F. Kennedy.

* AUTHOR’S NOTE: Barber and Harrison’s findings are, to some extent, supported by another acoustics expert, Robert Berkovitz. In 2006 Berkovitz had been asked by CNN journalist Brad Johnson to look at the Pruszynski Tape “…. preliminary to an analysis of all extant recordings made during the Robert Kennedy assassination and known and available to Johnson.  Johnson sought to hire us to analyze this material as part of a cable TV project, but nothing came of it.” Berkovitz emailed me and stated, “My final words to Johnson, shortly before he informed me of his withdrawal from the project, were that unless some way could be found to prove that the thumps or bangs in question were gunfire, any conclusions about their significance would rest on sand.  One question I would have wanted to answer was whether the relative amplitudes of the shot-like impulses in the numerous recordings could be used to locate their sources.” Berkovitz sent a spectrogram he had made in 2006 “……of a 4-second segment of the Pruszynski recording.  Audible impulsive events have been numbered, and we found eight of these.  The red-tinted rectangular portion at the left side of the spectrogram corresponds to a vocalization, 'Ow!' that follows the first event.  The more prominent event at the right side of the spectrogram, following impulse No. 8, is a scream.”