So who do you suggest corroborated Brehm? Altgens, the Connallys, Gayle Newman, William Newman, the Secret Service agents, Dave Powers, Ken O,Donnell, Mary Woodward, all contradict Brehm.
And Brehm contradicts them. Templin contradicts them.
So what? What's the point you're making? That the witnesses who suit you count and others don't?
And, as usual, you present witnesses who refute what you're saying:
Mary Woodward (11-23-63 newspaper article Witness From the News Describes Assassination written by Woodward for the Dallas Morning News)
"After acknowledging our cheers, he faced forward again and suddenly there was a horrible, ear-shattering noise coming from behind us and a little to the right. My first reaction, and also my friends’, was that as a joke, someone had backfired their car. Apparently the driver and occupants of the President’s car had the same impression, because instead of speeding up, the car came almost to a halt...
Then after a moment’s pause there was another shot and I saw the President start slumping in the car. This was followed rapidly by another shot."[patspeer.com]
Woodward describes the limo coming to "almost to a halt" before the second shot. We know from the Z-film this happens just before the headshot where she describes "the President start slumping in the car". She describes another shot after this.
Shot - headshot - shot after headshot.
And round and round we go.