Although I can see that JFK and Jackie and SS agent Hickey are reacting in sync beginning at Z140, I’m totally unconvinced that it was due to a loud shot from the TSBD at Z124.
Otherwise, then surely Rosemary Willis would be slowing down beginning at Z124 instead of at z190.
And surely at Z140 , JC would have turned his head left also in sync with JFK Jackie , since he said he heard the 1st shot.
So the Z124 1st shot idea is totally implausible and is also not supported by vast majority of ear witnesses that heard 3 shots in about 6 seconds ( 4 secs in the case of Harold Norman) and that the last 2 shots were back to back. That cannot be the case if the 2nd shot is Z223 and the 3rd shot is Z313 because that is a 4.8 sec span of time which no normal person would have perceived as “back to back” or 0.5 sec apart as Lee Bowers demonstrated to Mark Lane.
Andrew Masons proposed Z190 1st shot from TSBD does not work either if JC was hit by a bullet .at Z223 -z225. This appears to be the case as at Z223-Z227 JFK and JC are moving in sync and the very abrupt forward movement of JC’s upper torso and his right shoulder rotating is indicative that he had been hit by a bullet.
Andrew proposes that the JC reaction at Z225 is only due to hearing a shot 2 secs back at Z190. The abrupt movement of JC is supposedly just him attempting to turn his torso around leftwards to look back at JFK after earlier having failed to see JFK when he turned his head right.
The Z190 shot is tricky proposition to understand so I’m not entirely ruling it out because it has never really been determined as a fact , which way JC had his legs positioned at Z223.
My opinion about the position of JCs legs is that both left and right legs were together and turned about 45 degrees towards the right door. I base this opinion on 3 reasons:
1. When JC is seen again at Z223 , his upper shoulders and upper torso and head appear to be turned towards his right at about 45 degrees.
2. The jump seat that JC is sitting on is very close to the front seat that SS agent Kellerman is seated on. So JC probably had to sit in the seat at an angle so that his legs would not be pushing onto the back of SS agent Kellermans front seat. Since JC was going to be facing the Dealey plaza crowd located on the right side of the JFK limo, then JC most likely had his body and both his legs turned towards the right door of the JFK limo. This would be a much more comfortable position.
3. Based on the trajectory of the SBT , and that JC was gripping his hat upside down in his right hand when his hand moves abruptly upward in Z223-Z230 range , the well of that upside down hat would have had to be on the outside of his left leg if both his legs were turned about 35-45 degrees right towards the door.
Now I know Andrew has a diagram/ drawing which positions JCs legs spread apart and with JC holding his hat upside down between his legs. This position would not work with the SBT trajectory line as the bullet would have had to go thru JCs hat before it impacted his inner left thigh.
It’s easy just to avoid these problems by claiming that the SBT is false and devising a different sequence of shots as Andrew does by proposing the 2nd shot was at Z275-280 ish. That however , is also improbable due to the Altgens 6 photo at Z255 which establishes the SS agents have reacted to a shot from behind the JFK limo well before Z275-80. It is unlikely the SS agents at Z255 were reacting to a Z190 shot because their heads would have been turned by Z207 responding as Rosemary Willis has at Z200.
Based on these problems and mainly with the lack of reactions by SS agents from Z135-Z207 to look back at TSBD( Hickey although leaning does NOT look back) a 1st shot from TSBD at Z223 seems to me more probable than any 1st shot prior to Z223, except for the possibility of some suppressed shot by a 2nd shooter.
A straight-forward, common sense analysis.
The Altgens6/Zapruder analysis of the movements of the Secret Service agents is extremely strong evidence supporting a first shot aroundz222/z223.
As is the 40+ witnesses describing JFK reacting to the first shot, as seen after he emerges from behind the Stemmons sign.
As is the statements of all ten occupants of the Vice Presidential car and it's follow-up car placing their vehicles on Elm Street at the time of the first shot.
There is another extremely sound method of determining when the first shot occurred, using the observations of the eye-witnesses stood on Elm Street.
I did an analysis of their statements focussing on a single, salient point -
had the Presidential passed their location at the time of the first shot. It's a really simple and solid way of determining where the limo was on Elm Street at the time of the first shot.

The statements of the witnesses pictured above show, unanimously, that JFK had passed their position at the time of the first shot [statements lifted from Pat Speer's website]:
JUNE DISHONG: [taken from a letter written on the day of the assassination]
"His arm in the air waving… He drops his arm as they go by, possibly 20 feet. Suddenly--a sound. Gun shots? So hard to tell above the clamor of the crowd. The president bent forward into his wife’s lap as his arm slipped off the side of the car. Jackie circled him with her arm. Another shot. Panic among the people. Woman with children. Parents pushing them to the ground. No one knows where the shots are coming from. A cry. The President has been shot. A third shot, people scatter. I can't believe what I have seen. PEGGY BURNEY: [A first person account published in the Dallas Times-Herald the day after the assassination]
"When the President's car made the curve around the corner, he was smiling and waving...he was happy and Jackie was happy and smiling as they passed. The car had passed about 15 feet beyond me when I heard the first shot. I did not realize it was a shot; I thought it was a backfire. The President ducked; instinctively I told myself 'something is happening,' but nobody knew what."
JEAN NEWMAN: [ From a statement to the Dallas Sheriff’s Department on the day of the assassination]
"I was standing right on this side of the Stemmons Freeway sign, about halfway between the sign and the edge of the building on the corner… The motorcade had just passed me when I heard something that I thought was a firecracker at first, and the President had just passed me, because after he had just passed, there was a loud report, it just scared me, and I noticed that the President jumped, he sort of ducked his head down, and I thought at the time that it probably scared him too."ERNEST BRANDT: [Oral History interview performed for the Sixth Floor Museum, 5-12-94]
"He was kind of casually smiling…acknowledging the crowd and waving casually. Nothing had happened by the time the limo was exactly opposite us, from the curb straight out to the street. Nothing had happened. But I was still watching Kennedy from the back...And of course, all I could see above the back seat was his shoulders, his neck, and head…I think the limousine was probably about 60 or 70 feet past us, three or four seconds I guess from the time. It wasn't moving real slow but yet not real fast either, y'know. And--60 or 70 feet past us, then BAM! the first shot was fired and boy it just reverberated around Dealey Plaza something terrible."[11-22-95 article in the Dallas Morning News]
"Ernest Brandt, a salesman, watched from the curb as President John F Kennedy's motorcade turned down the Elm Street slope toward Stemmons Freeway... "Kennedy's limo was about 15 to 20 feet past us when the first shot was fired. I was still looking at him and I saw his arms come up." [July 2000 hand-written, 3-page letter from Brandt to researcher Don Roberdeau published in part on Roberdeau's Men of Courage website and posted in total on the alt.assassination.JFK newsgroup in 2009]
"President Kennedy was about 15 feet from me when the FIRST SHOT WAS FIRED!!! He was SLIGHTLY PAST ME at a "ONE O'CLOCK POSITION" in relation to my location on the NORTH SIDE of the Elm street curb.
JOHN TEMPLIN: [7-28-95 Oral History interview for the Sixth Floor Museum]
"Well, as the limo drew even with us, well, the president was waving and, of course, grinning. He had just a great big smile on his face...And just about, I would say, thirty feet past us, we heard what I personally thought was a motorcycle backfire, and I... the president kind of threw his shoulders up a little bit and kind of laid his head back on the back of the seat, and I thought, well, he’s just playing and playing the crowd and acting silly, you know.All five witnesses are unequivocal that JFK had passed their position at the time of the first shot. It is interesting to note that most of them note that JFK was waving and smiling just before the first shot, as we see him doing as he passes behind the Stemmons sign in the Z-film.
The best representation of where these witnesses were stood in relation to where the limo was at specific Z-frames is Don Roberdeau's map. When we map their positions in Dealey Plaza compared to the limo position at various Z-frames it becomes apparent that the first shot cannot have taken place any earlier than z222/z223.
