If you look at what the witnesses on the scene said directly after the event, the vast majority said they came from the direction on the School Book Depository. A gun barrel was seen sticking out of the sixth floor window. Workers on the fifth floor heard a bolt bring either above them, and shell casings hitting the floor. But yeah, go with the guys chasing the echoes.
I’m not saying there wasn’t a book building shooter. just that many people thought they also heard and/or saw action behind the grassy knoll fence - including cops on motorcycles riding just behind kennedy. They disembarked, ran up the hill, and were waved away by self-identified “secret service” men
it’s so ironic that you have an accused who gets silenced by a hood straight out of central casting, and people who think it’s suspicious are called “conspiracy kooks”