What are you basing, ".....almost 4 seconds between the first and second shots and almost 5 seconds between the second and third shots"? That's "almost" 10 seconds. That's a very long time and should have/would have attracted "eyeballs" from assorted Dealey Plaza positions toward the sniper's nest. According to Amos Euins, this did Not happen. "POW..............POW/POW"!
It is based on my calculations that the first shot was fired at Z147-148, the second at Z219-220, and the third at Z310-311. The first shot calculation is dependent on how I weigh the clues as to when the first shot was fired. There is no definitive proof as to when that shot was fired, but to me the best evidence dictates a Z147-148 shot.
