If so why did nobody on the steps notice a stranger in their midst?
Fred
Geez, Mr Clements, don't you get it yet? If Prayer Man was a stranger, then he wasn't noticed because everyone was focused on the motorcade. If Prayer Man was Mr Lee Harvey Oswald, then he was noticed because everyone was focused on Mr Lee Harvey Oswald who was already world famous which means Prayer Man can't have been Mr Lee Harvey Oswald.
It's quite simple really.