I am not sure what your definition of evidence is.
Over 20 witnesses recalled that JFK reacted immediately as if hit by the first shot. See this list of witnesses and their statements. Not a single witness said that JFK smiled and waved after the first shot, let alone for 3 seconds. So that is evidence that the first shot, not the second, struck JFK. That evidence is also inconsistent with a first shot before z186 (Betzner, motorcade witnesses, witnesses along Elm).
The problem is that there is a great deal of evidence that conflicts with a first shot before z186. There is no evidence that conflicts with a first shot after z186.
According to the evidence, all three shots struck either JFK or JBC. None missed................
I am not sure what your definition of evidence is.
I responded to your claim that all three shots found their mark. There's no evidence for that. In fact, it would be impossible. Less than a second passes between the time JFK is blocked by the Stemmons Freeway sign and when JBC is hit.
1) What the evidence shows is that JFK shows no signs of distress before the Stemmons Freeway Sign blocks him form the view of Zapruder at frame 208.
2) What the evidence shows is that by Frame 224 JBC suit lapel makes a rapid move forward indicating a bullet has passed through his body.
3) What the evidence shows is that by Frame 225 JFK is reacting to the automatic reflex known as the Thorburn position.
4) What the evidence shows is that the third shot hit JFK in the head and that either the first or second shot hit both JFK and JBC.
I have no problem with a claim that the second shot missed as LHO could still have had enough time to have fired a third shot, let's say first shot Frame 223, second shot missed around frame 250 (corresponds with Altgens testimony as to when he heard the first shot), third shot hit Frame 312. It's entirely possible, even probable, that Oswald was only using the iron sight for the first two shots and that would decrease the amount of time it takes to reload and fire by about 3/4 to a full second (12-18 frames). For the third and fatal head shot Oswald could have reaquired the target and fired in 3.3 seconds (62 frames).
While I agree there's earwitness testimony that places the first shot later than frame 186 I disagree there's no evidence of a shot before frame 186. The best evidence is the combination of the Zapruder film and the testimony of several witnesses plus Rosemary Willis can be seen on the Zapruder film running beside the presidential limo until she begins to slow down and turn her head to the left at frame 161. She later gave an interview in which she stated her reaction was due to a loud noise. This is in part why I agree with Gerald Posner that the sequence of shots were as follows;
1) Frame 160 missed
2) Frame 223 SB C-399 passes through JFK and JBC until it falls from his thigh and lands inside the pant cuff.
3) Frame 312 Fatal Head Shot