A majority of the witnesses said that the first explosion sounded different then the next two explosions.....Many of the witnesses thought that the first explosion sounded like a motor vehicle backfire or a large firecracker. I believe the sound they heard was in fact a "firecracker" which was the signal to the snipers that LBJ had signaled the team leader "open fire".
Did LBJ throw the firecracker himself or did he signal someone else to throw the firecracker?
Do we know what the signal was?
Maybe LBJ's signal was a firecracker that signalled the firecracker to be thrown to signal is was time to get to shootin'.
Surely the set-up would have to make people believe the shots came from the TSBD. How could they frame Oswald otherwise?
For at least five minutes after the shooting, 99% of the witnesses thought the shots had come from the GK. Virtually nobody thought the shots had came from the TSBD. This is a good example of people caving in to authority.... The police started reporting that they had found a "Sniper's Nest" ( an inflammatory description) shots had been fired from a "Snipers Nest" on the sixth floor of the TSBD...And thus the people who had heard the shots simply caved in and thought that they were mistaken, and went along with the police. ( read Orville Nix's account for a classic example of a witness who trusted the police more than he trusted his own good sense.)
Almost everyone in the building at the time of the shooting thought the shots came from inside the building but maybe these witnesses were futuristic cyborg manchurian candidates programmed to regurgitate the official line.
It's my opinion that if you wanted to set up someone firing from the TSBD you would have someone firing from the TSBD but I'm old-fashioned.