When I first saw the version of the Zapruder film that actually showed the driver, Secret Service Agent William Greer, and the front passenger, Agent Roy Kellerman, my first impression was probably like most who first saw it; damn, did the driver shoot Kennedy?!
The actions of both Secret Services agents are, to me, highly suspicious. Agents Greer and Kellerman both turn around at the same time and see Kennedy with his arms up by his neck gasping for air from being shot in the neck, then both turn back around at the same time as if nothing has happened. Then a second later, Greer turns around again to look at Kennedy as he slows the limo down while Kellerman leans back at the same time Greer turns around towards Kennedy, although Kellerman remains looking forward. Then Kennedy gets his head blown off right after Greer turns around and stares at him for the second time and then immediately after, Kellerman leans forward to duck down at the same time as Greer turns back around to the front and leans forward to duck down as he starts to speed away. It's as if both rehearsed their actions dozens of times.
What partially made me think that the driver might of done it was I only remember growing up seeing the Zapruder film version that didn't show the drivers and thought how weird it was that all this time seeing the film before, it didn't show the suspicious actions of the driver and front passenger Secret Service agents and after hearing the excuse Agent Kellerman gave as to why Greer turned around again makes it all the more unbelievable:
Between the second and third shots, however, [Kellerman] claims he shouted, "Let's get out of line, we've been hit," but that Greer apparently turned to look at Kennedy (for the second time), allowing Kennedy to be hit fatally, before accelerating the car out of the danger zone. As Roy Kellerman told author William Manchester, "Greer then looked in the back of the car. Maybe he didn't believe me."
After the initial astonishment wore off and I studied the actions of Greer closer, I concluded that he didn't shoot at Kennedy because it appeared that Greer wasn't holding a gun in his left hand:
Yellow circle showing William Greer's clenched left fist at the time Kennedy's head explodes. Notice his right arm is low on the steering wheel. (Photo source - #312. Note that I enlarged, sharpened, and brightened this still.)
However, after reading allegations that the Zapruder film might have been altered and then those allegations not seeming so far-fetched after I recently learned that the Zapruder film wasn't even shown to the public as a video until Geraldo Rivera first showed it in 1975 on Good Night America, more than 11 years after the assassination, I now wonder if Greer's left arm and hand had been altered if the Zapruder film had indeed been altered?
Now going back to look at the actions of both Greer and Kellerman and factoring in that the Zapruder film may have been altered, I just can't help wonder if Greer didn't whip around to his right with a gun in his left hand while slowing the limo down to pop Kennedy? Is it just another one of those bizarre coincidences that when you look at the film, it does in fact look like Greer did just that?
When looking at Greer with his left hand clinched in a fist in front of him with no gun in the released version of the film, a couple of things seem odd to me.
First, get in your car with both hands high and then low on the steering wheel, then whip around your right to look at the back seat where Kennedy would have been sitting. You'll notice that it would be your natural tendency to take your right hand off the wheel, not your left hand as Greer has appeared to do.
Second, while still in the driver's seat, whip around again back towards where Kennedy was, but this time pretend you're an assassin that has to shoot Kennedy. If the perps planned for the driver to turn around and shoot Kennedy and keep it as concealed as possible, they would most likely have hired a left-handed shooter because a right-handed shooter in the driver's seat would have to extend their right arm straight and all the way back to shoot at Kennedy thereby greatly exposing himself to on-lookers.
Now pretending you have a gun in your left hand, try whipping around to the back to shoot at Kennedy. Would it be easier for you to shoot at Kennedy with you right hand up high on the steering wheel, or down low on the wheel? I think it would be easier if your right hand was down low in the wheel, exactly the position of Greer's right arm. Having your right hand low on the steering wheel and whipping around with a gun in your left hand would be the best way for the driver to shoot at Kennedy and keep it as concealed as possible IMO.
Third, isn't it against protocol for a Secret Service agent, who is driving the President around in front of the public, to have their hands down low on the steering wheel, the position that would flunk you if you're taking a driver's test?
Here is Greer driving before Kennedy gets shot. Notice his hands are up high on the steering wheel; the correct driving position.
Both of Greer's hands are on the steering wheel as the limo was on Elm Street minutes before the shooting.
Forth, Greer having his left hand off the steering wheel clenched in a fist while looking back at Kennedy seems really odd to me. Why would he be clenching his hand in a fist like that? Does his left clenched hand even look natural coming down like that?
Notice that it looks as if Greer had his left hand up high on the steering wheel before dropping it down. Why would he have his left hand up high on the steering wheel and his right hand down low on the wheel if he wasn't preparing to turn around towards his right side to shoot at Kennedy with his left hand? Coincidence?
Fifth, notice that Kellerman, the passenger, had his hand covering his left ear right before the fatal shot as if he was expecting a shot coming from Greer. Another coincidence?
Lastly, if they are able to doctor the Zapruder film, they would obviously cover-up Greer's left arm and hand if he shoot at Kennedy with it.
Now even if the film has been doctored to cover-up Greer's shooting attempt, there would be some opposing questions even if Greer had shot at Kennedy, namely wouldn't Gov. John Connally's head have been in the way and if Greer did manage to hit Kennedy from the driver's seat, why does Kennedy's head go back and to the left and not back and to the right? I don't claim to have that answers to that, but let me say that just because I don't rule out that Greer may have whipped around to shoot at Kennedy doesn't mean I'm saying he actually shot him and delivered the fatal head shot that caused Kennedy's head to be thrown back and to the left. Some theorize that Kennedy was shot at at multiple angles when Greer slowed the limo down at the final kill-zone. Maybe Greer did shoot Kennedy, but his wasn't the dramatic head shot that looks to have came from the front also.
Whether Greer did shoot at Kennedy or not, Agent Greer's and Kellerman's suspicious actions that day are enough for me to believe that they were both in on it.