Charlie was killed at a specific location. How long was it known that he was going to speak on that spot? Or did Charlie not know and organizers directed him there on the day of the event? And was he seated when he was hit?
Whether a conspiracy or alone, to prepare for a long-range shoot, I think a shooter would have to know where their target would be. And if the target is offered a chair for a speaking engagement, its natural for them to sit down at some point. That’s when the target would be voluntarily immobilized for a careful aim.
I think knowing how the event was organized, promoted, and staged may proved clues as to who did the planning and their circle of acquaintances and friends. Possibly, there is a mole in that bunch who informed the shooter.
Apparently, that tent is always there. I guess it’s permanent place fir gatherings.