[previously...]
JF: However...regarding expert forensic evidence, a panel of sound engineers, acoustical specialists and various other auditory authorities told the HSCA committee that there is a 95% chance that there was a 4th shot from the knoll area.
MT: The "95%" claim was made by Wiess and Ashkenazy, no one else. Two guys.
[...and then...]
The study was supervised by Dr. James E. Barger, the firm's chief scientist. At the time of the reconstruction in August 1978, the committee was extremely conscious of the significance of Barger's preliminary work, realizing, as it did, that his analysis indicated that there possibly were too many shots, spaced too closely together, 5 for Lee Harvey Oswald to have fired all of them, and that one of the shots came from" the grassy knoll, not the Texas School Book Depository. When questioned about the probability of the entire third impulse pattern representing a supersonic bullet being fired at the President from the grassy knoll, Barger estimated there was a 20 percent chance that the N-wave, as opposed to the sequence of impulses following it, was actually caused by random noise.(65) Accordingly, the mathematical probability of the entire sequence of impulses actually representing a supersonic bullet was 76 percent, the product of a 95 percent chance that the impulse pattern represented noise as loud as a rifle shot from the grassy knoll times an 80 percent chance that the N-wave was caused by a supersonic bullet. (66)
The committee found no evidence or indication of any other cause of noise as loud as a rifle shot coming from the grassy knoll at the time the impulse sequence was recorded on the dispatch tape, and therefore concluded that the cause was probably a gunshot fired at the motorcade.
https://www.archives.gov/research/jfk/select-committee-report/part-1b.html
The Backyard pictures do not prove that Oswald killed JFK.
In retrospect...being plastered on the cover of LIFE magazine with the caption 'weapons used to kill Kennedy and Officer Tippit' instilled prejudice in the minds of Americans no matter the questions and no matter the circumstantial evidence.
The quote from the HSCA report you've presented doesn't rebut what I said. In fact, the quote supports my position. Weiss and Aashkenazi came up with the 95% number. The other acoustics group working for the HSCA, BRSW, looked at the WA study and immediately knocked the number down from 95% to 76%. If only they'd listened to the "garbled transmission" that they found at the time of the "shots."
As to your point about the photos not proving that Oswald shot anyone, you are correct in a strict technical sense. However, the BY photos are a link in a chain of possession that connects LHO to CE139.