A seemingly innocuous detail from the testimony of Ronald Fischer gave me a potentially new insight into the mind of the assassin in the moments immediately before the assassination.
Other researchers have the assassin stood up, firing into the street below him, bullets ricocheting off traffic light poles or firing through the oak tree, blasting through branches of the tree and other such nonsense -
as if the assassin hadn't already decided exactly what he was going to do beforehand and was instead just taking random potshots as the Presidential limo passed by the TSBD.
This is the relevant passage from Fischer's WC testimony:
"And I looked up and I watched the man for, oh, I'd say, 10 or 15 seconds. It was until the first car came around the corner of Houston and Main. And, then, when that car did come around the corner, I took my attention off of the man in the window and started watching the parade. The man held my attention for 10 or 15 seconds, because he appeared uncomfortable for one, and, secondly, he wasn't watching-uh---he didn't look like he was watching for the parade. He looked like he was looking down toward the Trinity River and the triple underpass down at the end-toward the end of Ell Street. And--uh--all the time I watched him, he never moved his head, he never-he never moved anything. Just was there transfixed."Fischer only looks away from the assassin because the motorcade has finally reached the end of Main Street.
In the 10-15 seconds he stares at this man, the assassin never looks to where the motorcade is coming into view. For that whole period of time the assassin stares in the direction of the triple underpass, he never moves his head, never moves his body, just stares towards the triple underpass - "transfixed".
What is it that the assassin is staring at?
Why does he seem uninterested in the motorcade?
What could possibly be of interest to the assassin down towards the triple underpass when his target, in the motorcade, is about to come into view in a matter of seconds?
In my opinion, it is the word "transfixed" that provides the key to understanding what is going on in the mind of the assassin.
He is visualising the kill zone.He has already decided exactly where he is going to assassinate his target.
As he looks towards the triple underpass he is aware of the oak tree but is more focused on the stretch of open road just beyond the oak tree. He has already decided that once the limo has emerged from behind the oak tree and is out in the open, he will pull the trigger.
The first shot does not occur before the limo has reached the oak tree.
It does not occur while the limo is obscured by the oak tree.
It occurs when the limo has emerged from behind the oak tree and is out in the open stretch of road just beyond the oak tree.
The open stretch of road the assassin has been transfixed on as the motorcade reaches the end of Main Street.
In perfect agreement with the first shot at z222/223 I've been arguing for in the bulk of this thread

Above is the view from the SN window the assassin was staring at, "transfixed".
As far as the assassin is concerned there is only one feature of interest -
the open stretch of road beyond the oak tree.
It is at this point the limo will be moving almost directly away from him, with minimal lateral movement.
It makes perfect sense that the assassin has already made up his mind regarding his plan of action.
The idea that he starts taking random potshots as the limo passes the TSBD won't fly. The idea that he is rushing so much he needs to fire through the oak tree won't fly.
Look at the picture above, if you were the assassin, when would you pull the trigger?