Thanks for your collegial comments.
The HSCA concluded there had been a gunshot from the GK, and certainly many witnesses thought so. Sam Holland and co-workers thought they saw smoke on the GK.
Modern guns can and do smoke, depending on the ammo, and how recently the barrel has been lubed. A snub-nose .38 gives off more smoke than guns with longer barrels, and makes a louder bang, and is easily concealed. Even gun enthusiasts report lots of smoke from "cheap ammo" such as the "Egyptian" brand.
A Dallas sheriff and a Dallas PD officer both said they encountered a man flashing Secret Service credentials on the GK.
As for the acoustical evidence...I don't understand any of it.
I can see the Z-film on line, frame by fame, draw my own conclusions.
So as I say, IMHO, caveat emptor, and draw your own conclusions.
The HSCA did not conclude there was a gunshot from the GK.
Here is what they said (note the qualifiers in the phrasing):
A high probability is not a conclusion. And "other scientific evidence does not preclude the possibility of two gunmen" is not a conclusion either.
