Howard Brennan gives us an account of when he heard the first shot in his affidavit dated 11/22/63 that also has two specific stationary points we can use in a similar fashion. So if we draw a straight line from where Brennan was sitting to the last [western most] window in the south wall of the TSBD, we are basically in the same area that Victoria Adams' account describes for the first shot in her account. Two independent accounts that have more precision than most accounts corroborate each other and they both are indicative of a first shot around the time of z-133. This is significant in my opinion.
Do you mean this from Brennan?
"I proceeded to watch the President's car as it turned left at the corner where I was and
about 50 yards from the intersection of Elm and Houston and to a point I would say the
President's back was in line with the last windows I have previously described I heard
what I thought was a back fire."
By "last windows I have previously described", he's referring to the SN window, not the west-most set of windows on the sixth floor.
And "the President's back was in line with" I take to mean the back facing to the SN window. Kennedy's back faced more directly towards the SN window the further the car traveled down Elm street. To me, that would make it compatible with a Z220s shot. Brennan, I believe, at one point could only relate events to him having heard two shots.