1978 House Select Committee on Assassination released its report stating that their acoustic experts had proven through scientific testing to a 95% or greater certainty that there were at least 4 shots fired from at least 2 separate directions. The audio was taken from a police motorcycle allegedly riding 8 cars behind the president. The officer, H.B. McLain, had a stuck microphone and the audio was recorded on a dictabelt machine. The recording contains the impulses of at least 6 and possibly 7 shots. The open microphone effectively jammed radio channel at the time of the assassination and for quit sometime afterwards. The Committee’s Acoustic Experts went to Dallas and fired and recorded the sounds of test shots from the “Oswald window” and the “grassy knoll.” They compared the acoustic audio impulses and echo patterns to those on the original tape. The 1st, 2nd and 4th shots all came from the behind the car and the 3rd came from the grassy knoll proving a second shooter and a case for conspiracy. The 3 additional shots were dismissed by the Assassination Committee because the echo patterns did not match patterns of the test shots. The other 3 shots were fired from a minimum of an additional point proving a 3rd shooter. The first 2 confirmed shots, both from behind the president, were fired 1.6 seconds apart, not enough time - 2.3 seconds – to come from the “Oswald rifle” proving a 4th shooter. Six sequences of impulses that could have been caused by a noise such as gunfire were initially identified as having been transmitted over channel 1. The echo patterns in a complex environment such as Dealey Plaza are unique, so by conducting the reconstruction, the committee could obtain unique "acoustical fingerprints" of various combinations of shooter, target and microphone locations. The fingerprint's identifying characteristic would be the unique time-spacing between the echoes. If any of the acoustical fingerprints produced in the 1978 reconstruction matched those on the 1963 Dallas police dispatch tape, it would be a strong indication that the sounds on the 1963 Dallas police dispatch tape were caused by gunfire recorded by a police microphone in Dealey Plaza. https://www.archives.gov/research/jfk/select-committee-report/part-1b.html The audio recording lasts for roughly five and a half minutes and begins at 12:20 pm, a minute before the assassination took place. The full audio can be found here. https://nap.nationalacademies.org/readingroom.php?book=JFK_audio&page Clip taken from JFK: The Case for Conspiracy [DVD] - Proof of Conspiracy - Exclusive films - Autopsy Photos – Produced by Robert J. Groden, Chief Photographic Consultant to the House Select Committee on Assassination and Technical Advisor to Oliver Stone’s “JFK” Now you can see for yourself what really happened on November 22, 1963. Robert J. Groden is acknowledged as the world’s foremost authority on the photographic evidence relating to JFK’s assassination. Here, for the first time, are his optically enhanced films and photographs from that dark day and the investigation and cover-up that followed. Mastered from Mr. Groden’s original materials. DVD Release date: ‎ November 18, 2003