How many seconds past Holland's putative "first shot" would that be?
Hard to say?
-- MWT
In "Lost Bullet", Holland claims the first shot occurs as the President went beneath the right-lower corner of the traffic light assembly hanging at the end of the arm.
Holland claims the total shooting sequence was 11.3 seconds (about 207 Zapruder frames). Working back from Z313, Holland's first shot is about 27 frames (1.5 sec) before Z133. The Euins/PA Donaldson segments in "Lost Bullet" show the limousine stopped at Z134 (possibly Holland was trying for Z133 as he once used that as a reference point).
From Z134 to Z157 (approx. first shot proposed by some LNers) is 1.3 sec. Therefore, Holland's first shot is 2.8 seconds before the area most LNers place the first shot.