Secrets of the Zapruder Film
Ken Scearce & Brian Roselle



Secrets of the Zapruder Film Contents

A.    The “Ur Text” of the JFK Assassination

B.    Only a Matter of Time

C.    History of Shot Timing Controversy

C1. Link between shot timing and perceptions about Oswald’s sole guilt
C2. Initial shot timing: the Secret Service’s analysis
C3. Early news media shot timing analysis
C4. Governor Connally’s earliest recorded statements about the assassination
C5. Warren Commission shot timing analysis
C6. Criticism of Warren Commission’s shot timing analysis
C7. Connally stokes mounting doubt
C8. 1967 CBS News shot timing analysis
C9. HSCA shot timing analysis

D.   Currently Prevailing Consensus of Timing of the First Shot

E.   New Shot Timing Challenging Prevailing Consensus

E1. Presumptive shot timing
E2. New evidence in Zapruder film of first shot’s timing
E2.5 Other reactions observable in early frames of the Zapruder film
E3. Application of perception-reaction time science to prevailing consensus theory
E4. Weaknesses of other support for prevailing consensus
E4i. Camera movement analysis
E4ii. Tree ricochet theory

F.    Summary of Shot Timing Analysis History

G.    Implications of longer shot timing

H.    Areas for further study


A.   The “Ur Text” of the JFK Assassination

Amateur photographer Abraham Zapruder famously recorded President Kennedy’s assassination with his home movie camera.  Zapruder’s film, one of several taken as Kennedy’s limousine drove through Dallas’s Dealey Plaza, was quickly recognized by law enforcement as, by far, the most forensically valuable photographic record of the crime.   Subsequent investigations confirmed this initial judgment: the other films and photographs captured only instants or brief moments, from mostly unfavorable vantage points.  The Zapruder film, with its significant length and continuous close focus on Kennedy, has achieved universal stature as “the canonical ur text of John F. Kennedy’s assassination, the most complete and most chilling visual record.”1

For over 50 years, the prevailing belief has been that Zapruder was filming while each shot was fired at President Kennedy, so that the film is almost universally thought to be a “start-to-finish record of the president being shot.”2  Yet the Zapruder film itself has always contained a humble secret: it is not a record of the entire shooting, as this presentation shows.   Why the unfounded belief in the Zapruder film’s completeness came to be is not clear.  Perhaps it has had something to do with exceptionalist qualities our culture projects onto famous people, events and objects.  A more prosaic explanation is, simply, lack of knowledge.  This presentation examines historical interpretation of the Zapruder film to reveal the secret its images have always contained, hidden from us not by the film itself but by our own projections onto the film and our ignorance of its contents.

B.  Only a Matter of Time

Theories abound as to the number of shots fired during the assassination, but the best evidence is that three shots were fired.3  The first recorded eyewitness account, dictated by a UPI reporter within four minutes of the shooting, stated, “Three shots were fired at President Kennedy’s motorcade . . . . “  Of the dozens of witnesses who have spoken about how many shots they heard, the lion’s share reported hearing three shots.  Three spent shell casings were found in Oswald’s “sniper’s nest” in the building from which he shot Kennedy.  No valid evidence has ever been found of another shooter, or other shots.

Because of the strength of the evidence that three, and only three, shots were fired, the most challenging issue about the shooting has always been not how many shots were fired, but how long the shooting lasted.  This question relates directly to the greatest controversy about the Kennedy assassination:  whether Oswald accomplished the murder alone.


C.  History of Shot Timing Controversy

C1.  Link between shot timing and perceptions about Oswald’s sole guilt

The question of Oswald’s sole guilt probably would never have arisen had Oswald not himself been murdered while in police custody two days after Kennedy’s murder: the evidence against Oswald was quickly shown to be solid, and no evidence of plural guilt was being found.  From the time of the assassination until Oswald was killed, virtually no one was seriously speculating about assassins.  But Oswald’s murder raised the specter of conspirators silencing a co-conspirator.  Almost immediately after Oswald’s killing, the question was raised:  did Oswald have enough time to do this by himself?

C2.  Initial shot timing: the Secret Service’s analysis

The Secret Service obtained copies of the Zapruder film on the same day as the assassination. Five days later, on November 27th, the Secret Service staged a re-enactment of the assassination in Dealey Plaza, using the Zapruder film to determine the moments when each of the three shots was fired. 

From this re-enactment, Secret Service investigators concluded that the three shots were fired within frames 210 – 313 of the Zapruder film, a time period of 5.6 seconds.  This timing was based on the wounding effects the Secret Service could see in the film.  At frame 225, Kennedy emerges from behind a road sign already reacting to being wounded.  It was unclear to the Secret Service whether Kennedy was shot at frame 225, or a split-second before, so it allowed about one second of prior leeway to account for this uncertainty.  Texas Governor John Connally, sitting directly in front of Kennedy, also reacts to being wounded after frame 225, but the exact timing of Connally’s wounding was not clear to the Secret Service.  The timing of the shot to Kennedy’s head is horrifyingly clear at frame 313.

Ultimately, the Secret Service investigators concluded that Kennedy and Connally were shot separately, with Kennedy being wounded first, in the neck.  The thought did not occur to the Secret Service then, although we know it to be fact now, that Connally was wounded by the same shot that first wounded Kennedy.  Since the shot at frame 313 seemed to fix the end of the shooting sequence, the total shot timing, according to the Secret Service’s reconstruction, was – at most – 5.6 seconds. 

The Zapruder film frames prior to frame 225 looked to the Secret Service investigators to be mostly uninteresting because, to their eyes, nothing of significance could be seen in the earliest frames of the Zapruder film.  From frame 133, the beginning of the assassination sequence, to frame 225 when Kennedy’s wounding first becomes clear, the Zapruder film shows Kennedy sitting in his limousine proceeding down Elm Street, waving to the cheering crowd, and disappearing momentarily behind a road sign – then emerging from behind the sign at frame 225 obviously wounded.  These early Zapruder film images looked benign to the Secret Service investigators. 

The Secret Service noticed that from Oswald’s point of view, a tree interfered with Oswald’s view of Kennedy during a sequence that roughly matched the time between Zapruder frames 166 to 210.  The Secret Service thought it obvious that Oswald would have held off shooting until his view of Kennedy was no longer obstructed by the tree. For the Secret Service investigators, this observation about the tree confirmed their analysis that Zapruder’s film showed that all three shots were fired after frame 210. 

In their rush in the days just after the assassination to determine the shot timing and sequence, the Secret Service investigators blinded themselves to consideration of the possibility that the Zapruder film actually showed a shot timing longer than 5 to 6 seconds.  The FBI, in charge of the overall investigation of the assassination but deferring to the Secret Service’s findings from its re-enactment, adopted the Secret Service’s 5.6 second shot timing along with the Secret Service’s hasty conclusion that Kennedy was shot first, then Connally shot next, then Kennedy shot again, in the head.4  This initial relatively rapid shot-timing proved to have decades-long consequences.

C3.  Early news media shot timing analysis

Within days of the Secret Service re-enactment, the American news media learned of the “official” shot timing, perhaps via FBI leaks, or simply from reporters having overheard Secret Service agents discussing their findings during the re-enactment in Dallas.5  A December 4, 1963 New York Times article related that “[f]rom motion pictures of the President’s assassination . . . authorities have concluded that the three shots were fired over a period of five to five and one-half seconds” while noting that “some persons have continually expressed skepticism that one man could have fired the three bullets so rapidly.”   Rounding off the rapid-timing scenario, an essay in LIFE magazine’s December 6th issue titled “End to Nagging Rumors: The Six Critical Seconds” sought to debunk “breathless rumors” of conspiracy with a reassuring assertion that Oswald could have fired that quickly.

These and similar news reports in the first few weeks after the assassination had the effect of “locking in” for the American public the idea that the shooting took no more than 6 seconds, that achieving his deadly accuracy in this short amount of time was not difficult for Oswald, and that questions over the plausibility of this rapid-shooting scenario were unfounded.

C4.  Governor Connally’s earliest recorded statements about the assassination

While the official investigation continued and the news media continued to debate the 6-second shot timing, other evidence began to emerge that would, over time, inform analysis of how long the shooting took.

In a televised interview on November 27, 1963 broadcast live from his hospital room, Connally made his first recorded statement about the assassination.  During this interview, Connally recounted his reaction to hearing the first shot:

"And then we had just turned the corner.  We heard a shot.  I turned to my left.  I was sitting in the jump seat.  I turned to my left to look in the back seat.  The President had slumped.  He had said nothing.   Almost simultaneously, as I turned, I was hit, and I knew I had been hit badly."

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Two weeks later, on December 11, 1963, Connally was interviewed by the FBI.  This time, Connally, gave a different description of his first reaction to hearing the first shot:

We don’t know why Connally gave different descriptions of the direction – left, versus right – in which he first turned in response to hearing the first shot.  Perhaps it was not until after his November 27 interview that Connally learned, or clearly grasped, that Oswald was positioned to his right rear; if so, this would explain the discrepancy, but it would also mean that Connally altered his explanation of the event to fit newly-learned information. 

Connally’s recollections of the direction he first turned in reaction to hearing the first shot would prove to be crucial to the question of how long the shooting lasted.  The important point to observe here is that Connally’s first recorded statements on this point conflicted.

C5.  Warren Commission shot timing analysis

Millions of words have been written castigating the Warren Commission for its failures in investigating the assassination of President Kennedy.  Most of these criticisms are fatuous, but some have merit.  Supreme Court Chief Justice Earl Warren declared to his fellow commissioners that “our only client is the truth,” but the Commission was hoodwinked by the CIA which withheld the fact that it had plotted to assassinate Fidel Castro, and by the FBI which hid evidence it had destroyed a note it received from Oswald a few weeks before the assassination warning the FBI against bothering his wife.  These startling revelations (not revealed until the mid-1970s) and other missteps by the Warren Commission grievously wounded its reputation for diligence and success in finding the whole truth. 

But the general opprobrium that now prevails about the Warren Commission’s work has thrown the baby out with the bathwater.  Lost in the widespread and damning criticism is the fact that the Warren Commission achieved key insights into the assassination that had escaped the vaunted investigatory talents of the Secret Service and the FBI. 

Stated simply, the Warren Commission realized – contrary to the Secret Service and FBI conclusions – that one shot missed the limousine and its occupants.  The Commission declined to commit itself to determining which shot missed, calling the evidence “inconclusive.”6   But in determining that one shot missed, the Warren Commission was left with only two shots to account for Kennedy’s and Connally’s wounds.  Since one of the three shots hit only Kennedy’s head, the fact that a shot missed implied that Connally and Kennedy were struck by one bullet.7  This new explanation became known as the “single-bullet theory.”  The Warren Commission’s single-bullet explanation and missed shot finding were major forensic advances over the hasty and flawed conclusions of the Secret Service and the FBI.  

Despite this breakthrough, the Warren Commission confronted a troubling problem:  Governor Connally insisted, in his testimony before the Commission, that he had not been wounded by the first shot and – crucially – that the first shot hit Kennedy without hitting himself.

Connally’s testimony implied that none of the three bullets missed.  If Connally was correct, then the single-bullet explanation could not be correct because it depended on one shot missing. 

Although Connally had told the FBI in December 1963 that he merely “sensed” that Kennedy was wounded by the first shot, Connally maintained a confident belief that he was correct.8   In fact, as the Zapruder film clearly shows, Connally did not turn far enough to actually see Kennedy until after the second shot.  No one confronted Connally with his failure to actually see what he proclaimed as fact.   

Perhaps impressed with Connally’s gravitas as a political figure and uniqueness as a witness to the shooting, several Commission members voiced deep unease about the single-bullet explanation.   The Occam’s Razor reconciliation of Connally’s subjective beliefs with the objective evidence – that Connally was just plain wrong in thinking that Kennedy was wounded by the first shot – did not outweigh Connally’s eminence for the Warren Commission, as the evidence shows it should have.

Connally’s confidence-rich but evidence-poor beliefs caused lasting harm.  In treating Connally with deference, the Warren Commission failed to grasp the poverty of his objections to the “first shot missed” scenario, which went ineluctably hand-in-hand with the single bullet theory.   As a result, the Commission put the “second shot missed” 6-second timing on an equal footing with other scenarios even though, if the second shot missed, Connally’s beliefs made no sense. To its credit, the Warren Commission recognized that if the first shot missed, the shot timing had to be longer than 6 seconds – several seconds longer, if Oswald was not shooting as rapidly as possible.9  But the Warren Commission’s complacent acceptance of the plausibility of Connally’s “first shot hit” version left it vulnerable to criticism – raised even in the days just after the assassination –  of the strained timing needed to fit the three shots within the 6 seconds of the 210 – 313 Zapruder frames.10  

Frustratingly, while giving undue credence to Connally’s merely subjective “sense” of what happened, the Warren Commission limited its evaluation of the most objective evidence: the Zapruder film.   With few exceptions, the Warren Commission closely studied only frames 171 through 334 of the film.  As had the Secret Service and the FBI, the Warren Commission saw nothing of significance to the shot timing in the Zapruder film frames 133 through 170.  In time, others would do this work – looking closely and skillfully at the earliest Zapruder film frames – which the Commission should have done itself.

C6.  Criticism of Warren Commission’s shot timing analysis

Because of the Warren Commission critics’ oversimplified characterizations, the popular perception somehow formed that the Warren Commission had actually committed itself to a shot timing of no more than 6 seconds.  After consideration of the critics’ challenges, this rapid-fire scenario justifiably struck most people as implausible.  The once easily-explained “six critical seconds” morphed into criticism of the six-second shooting scenario.  Eventually, the “6 seconds” scenario became a meme – cultural shorthand – for rejection of the official explanation, most concisely summarized by the title of Josiah Thompson’s 1967 book, Six Seconds in Dallas.11

C7.  Connally stokes mounting doubt

The dogged and mounting attacks of the Warren Commission critics reached a crescendo in 1966.  Mainstream media, sensing a sea-change in public opinion, began to take a more generous view of the critics’ arguments, and a second look at the Zapruder film.

In a November 25, 1966 cover article titled “A Matter of Reasonable Doubt,” LIFE magazine re-assessed the plausibility of Oswald’s sole guilt after inviting Connally to review high-quality blowups of frames of the Zapruder film, at that time owned exclusively by LIFE.   After examining the Zapruder film closely and declaring that it proved he was not yet wounded after Kennedy was clearly already reacting to his wound from the first shot, Connally stated:

“ . . . There is my absolute knowledge, and Nellie’s too, that one bullet caused the President’s first wound, and that an entirely separate shot struck me.”

“It’s a certainty,” said the governor, “I’ll never change my mind.”

This startling LIFE magazine article was read intently by millions of Americans and stoked public doubt about the correctness of the Warren Commission’s conclusion that Oswald acted alone.

C8.  1967 CBS News shot timing analysis

LIFE called for a new government investigation of the Kennedy assassination in light of Connally’s Zapruder film analysis, but the government did little in response.  Other media organizations observed the keen public interest and took up the challenge to re-investigate the assassination.
The most important of these news media reexaminations was undertaken by CBS News in 1967.  In a wide-ranging reassessment broadcast over four consecutive evenings in June 1967, CBS examined many of the critics’ arguments and reevaluated the most vexing evidence, with a heavy focus on application of forensic science.   Crucially, CBS took a deeper, broader and more insightful look at the Zapruder film than had the Warren Commission and in doing so, reached new insights.

CBS’s program, called “A CBS New Inquiry:  The Warren Report,” achieved several important advances over the Warren Commission’s work. 

First, based on no more evidence than the Warren Commission had, CBS recognized and declared that the shot that missed was the first shot. 

Second, despite Connally’s recently-declared “certainty” that the single bullet theory was wrong, CBS concluded that it was right, though it couched the single bullet explanation in the language of science, as “probably” correct. 

Third, in its most innovative analysis, CBS applied the work of University of California physicist Luis Alvarez evaluating whether the Zapruder film contained evidence of the shot timing different from the wounding effects evidence the Warren Commission had studied. 

In late 1966, upon reading LIFE magazine’s “A Matter of Reasonable Doubt” article, Alvarez became keenly interested in the Kennedy assassination and particularly in the application of scientific techniques to interpretation of the Zapruder film.  Alvarez had studied the concussive effects of the first nuclear explosion at Los Alamos in 1945 and wondered whether the shots Oswald fired had an analogous effect on Zapruder’s steadiness with his camera.  Studying the Zapruder film intently, Alvarez noticed subtle, single-frame blurs in certain Zapruder film frames, and hypothesized that the shots had caused Zapruder to flinch, causing the blurs. 

CBS tested Alvarez’s theory by having volunteers film with 8mm movie cameras like Zapruder’s while rifle shots were fired from a platform in a tower replicating Oswald’s height and distance from Zapruder.  The results of this test were shown to the CBS audience in the following segment:

[Walter Cronkite]:  Just as a rough check on this theory, we decided to try it ourselves, using other cameramenholding similar cameras, standing on a rifle range, filming an automobile while a rifleman fired over their heads.These two volunteers are aiming their cameras at a parked limousine.  Their instructions:  “Hold the cameras assteady as possible, and keep filming no matter what happens.” . . .  The reaction was obvious.  The film taken by;these cameramen showed the effect of the shots, despite instructions to hold steady.

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CBS showed that the camera operators flinched when the rifle shots were fired, even when told to hold their cameras steady.  In other words, they reacted involuntarily.  Their films showed subtle blurs, similar to those visible in Zapruder’s film, caused by their involuntary reactions to the gunshot sounds.

CBS’s analysis studied what is known to science as the “startle response.”  The startle response (sometimes referred to as the “startle reflex”) is a pattern of involuntary body movements in reaction to a threatening stimulus.  In a study published in 1939, scientists Landis and Hunt analyzed human reaction to a particular threatening stimulus:  the sound of a gunshot.  Using high-speed motion picture cameras, Landis and Hunt found that humans reflexively flinch involuntarily upon hearing a gunshot with a slight forward movement of the head and neck, protective hunching of the torso, and blinking.   

We can see from the 1967 CBS test what the startle response for Zapruder would be like to hearing a gunshot.  The movement is subtle, which makes it harder to see the farther the observer is from the reacting subject.  It cannot be resisted, due to its reflexive nature.  It is sudden, and very brief. 

Alvarez recognized that the startle response is useful in analyzing the timing of gunshots in the Zapruder film because it can help distinguish between voluntary and involuntary movement of Zapruder’s camera.  Most of Zapruder’s camera movements were voluntary as he tracked the presidential limousine left to right and up to down across his field of view.  Even very unsteady and rapid movements by Zapruder were usually voluntary; for example, Zapruder’s jerky camera movements during frames 189- 197 as he “hunted” for his subject while it was disappearing momentarily behind the road sign.  But sudden, single-frame camera accelerations in the Zapruder film are probably involuntary, and strong evidence that – at those moments – Zapruder flinched in response to a gunshot.

The Zapruder film shows with clarity the instants that the second and third shots struck:  the second shot at about frame 222 and the third shot at frame 313.12   Two sudden camera accelerations at frames 227 and 318 correspond with these visible effects of the second and third shots; at frames 227 and 318, Zapruder’s camera accelerates suddenly with downward and horizontal motion, causing blurring, as shown below:

Frames 222 - 227


Closer Up On Frames 226-227

Film blurs at frame 227 as camera moves


Frames 313 – 318


Closer Up on Frames 317-318

Film blurs at frame 318 as camera moves

The Zapruder film shows that there was a delay of about 5 frames (about .25 seconds) between the instants the shots struck at frames 222 and 313 and Zapruder’s involuntarily startle responses.  This pattern gives us a rough measure of the probable delay between Zapruder’s perception of Oswald’s first shot and Zapruder’s first startle response.

Applying this approximate delay between shot sound perception and sudden camera acceleration, CBS News presented the theory that Zapruder’s camera accelerated suddenly at about frame 190 and that the first shot happened at about frame 186.  CBS News noted, as possibly confirming evidence, that Oswald would have seen a momentary gap in the tree branches at frame 186 and may have chosen that moment for his first shot at Kennedy. Under the scenario presented by CBS, the shooting took more than 6 seconds.  For CBS, this expanded shot timing lessened doubt about the single-bullet theory and made Kennedy’s assassination more plausibly the work of one person.

C9.  HSCA shot timing analysis

Although CBS’s 1967 investigation concurred with the Warren Commission’s major findings and quieted the JFK assassination controversy temporarily, by the mid-1970s public doubt billowed again with the first public broadcast of the Zapruder film and its clear evidence that the third shot caused Kennedy’s head to jerk backwards toward Oswald.  When this fact became widely known in 1975, post-Watergate America no longer scoffed at the Warren Commission critics’ political conspiracy theories. 

Renewed demands for an official re-investigation culminated in the formation of the House Select Committee on Assassinations (the HSCA), which re-examined President Kennedy’s murder in the late 1970s.  As had always been the case, the Zapruder film and the question of the shot timing again occupied center stage.

Connally testified before the HSCA about his reactions to hearing the first shot, saying:

"I thought the shot came from back over my right shoulder, so I turned to see if I could catch a sight of the President out of the corner of my eye because I immediately had, frankly, had fear of an assassination because I thought it was a rifle shot."

Connally had made similar statements previously about turning in response to hearing the first shot.   As noted above, Connally had first stated (to a national television audience) that he turned to his left.  He then told the FBI that he turned to his right.  Before the Warren Commission in April 1964, Connally testified:

"We had just made the turn, well, when I heard what I thought was a shot. I heard this noise which I immediately took to be a rifle shot. I instinctively turned to my right because the sound appeared to come from over my right shoulder, so I turned to look back over my right shoulder, . . . ."

Connally also demonstrated his turn in several occasions.  For example, in a June 22, 1964 television interview, Connally stated:

"I heard this shot.  And I say “shot” because I immediately thought it was a shot. I immediately thought it was a rifle shot. . . . And I turned thinking that the shot had come from back over my right shoulder."

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Connally does in fact turn his head quickly in the earliest frames of the Zapruder film: The excerpt below is a close up from frames z136-z180.

But as we can see, Connally turns his head to his left just before turning his head to his right.  Connally’s leftwards head turn took only a ¼ of a second, from frames 150 – 155.  Connally then turns his head right from frames 162 – 167, another ¼ second head turn. Connally’s leftwards, then rightwards head turns are started and completed within one second, between frames 150 – 167. 

In its final report, the HSCA did not comment on Connally’s leftwards head turn from frames 150 – 155.  Perhaps the HSCA investigators did not notice it.   The HSCA report states:

The first reaction by any of the limousine occupants to a severe external stimulus begins to occur in the vicinity of Zapruder frames 162-167.  At this time, Connally is looking to his left, when his head begins a rapid, sudden motion to the right. . . .   Although it is apparent that none of the limousine occupants has been shot at the time that Connally initiates this movement, the Panel considers these actions to be particularly significant because they were consistent with his Warren Commission testimony that he turned in response to having heard the first shot . . . .

The HSCA concluded that Connally’s rightwards head turn starting at frame 162 was “[t]he first reaction by any of the limousine occupants to a severe external stimulus . . . .”  However, as we can see from the close-up of Connally above, Connally’s left-right head turns began at frame 150, and were both so rapid that both were probably a reaction to “a severe external stimulus.”  Although Connally spoke many times of turning to his right in reaction to the first shot, he was not always consistent; Connally’s first recorded statement was that he initially turned to his left. 

The HSCA found what it thought was corroborating evidence for its conclusion that Connally reacted in frames 162 – 167 to the first shot, in the movements of a young girl in the early Zapruder film frames.  The HSCA report states:

During the period of Connally’s initial rapid movement, however, no one else shows a comparable reaction.The President does not appear to react to anything unusual prior to Zapruder frame 190.  The Panel observed, however,that at approximately this time, a young girl who had been running across the grass, beyond the far curb of the street where the limousine was travelling, suddenly began to stop and turn sharply to her right, looking up the street in adirection behind the limousine.

In contrast to its specificity about the moment of initiation of Connally’s reaction to the first shot began, the HSCA did not determine the probable beginning of the young girl’s reaction.  This presentation addresses that overlooked issue below.

In addition to looking at possible reactions to the first shot by people visible in the Zapruder film, which the Warren Commission and CBS had not done, the HSCA extended CBS’s startle response/camera movement analysis by looking for possible gunshot startle reactions by Zapruder throughout the entire film, CBS having looked only at Zapruder film frames starting in the 170s.  HSCA analysts pointed to several episodes of blurring in the Zapruder film, among them blurring “at frames 158-160.”   The HSCA report noted a possible link between this blur episode and Connally’s head turn beginning at frame 162; in this regard, the HSCA’s report states:

Another shot could have caused the blur episode D at frames 158-160.  It occurs much earlier in the motorcade thanhad been considered possible for a shot by either the Warren Commission or most Warren Commission critics. . . .  The most interesting thing about this hypothetical shot is that Mrs. Kennedy and Governor Connally testified before the Warren Commission and Governor Connally testified before the select committee that they turned to their right when they heard the first shot, and both are seen in the film beginning a turn to the right immediately after this hypothetical shot. This appears particularly striking in the case of Governor Connally, whose head turns from midleft to far right in less than half a second, beginning at frame 162.

The HSCA camera movement analysis found several episodes of blurring and panning errors, which its report showed in the following graphs:

The HSCA ranked these blurring/panning error episodes from highest to lowest severity as follows:  312-318, 189-197, 220-228, 158-160, and 290-293. 

If we disregard the blurs/panning errors in frames 189-197, as we should since this was voluntary movement by Zapruder in “hunting’ for his subject as it was about to disappear behind the road sign, and the blurs/panning errors in frames 290-293, as we should since there is no other evidence that a shot was fired between frames 223 and 313, the remaining three largest blur/panning errors are in the vicinity of frames 157, 227 and 318.


D.   Currently Prevailing Consensus of Timing of the First Shot

In the years since the HSCA’s investigation, a consensus arose that Oswald’s first shot  – the shot that missed –  was fired at around Zapruder frames 155-157. One of today’s leading analysts of the Zapruder film, Dale Myers, summarized this consensus about the first shot’s timing on his Kennedy assassination-focused website “Secrets of a Homicide.”  There, Myers states:

Those who have studied the Zapruder film know that the film itself contains the best evidence of a shot fired immediately prior to Z160 as seen in the actions of Mrs. Kennedy, Mrs. Connally, and Governor Connally. All three react exactly as they testified that they did immediately after the first shot. Their actions, contemporary to the first shot, occur no where else in the film. Assuming a quarter of a second reaction time (a typical human startle response time) puts the first shot about 5 frames before Governor Connally’s reaction beginning at Z162, hence (Z155–157).13
The linchpin of the consensus first shot timing is that Connally’s rightwards head turn starting at frame 162 was an involuntary startle reaction by Connally.  Other evidence advanced for the consensus timing includes the camera movement in the vicinity of frame 157, and the belief that the branches of the tree may have deflected a shot fired in the vicinity of frame 157. 


E.   New Shot Timing Challenging Prevailing Consensus

E1.  Presumptive shot timing

Since the second and third shots give us a clear example of the amount of time between those shots that Oswald thought necessary to achieve accuracy, we should use the 5-second gap between those shots as the presumptive time between first and second shots, then examine whether the evidence tends to support, or refute, that presumptive timing.  Analyzed in this way, the presumptive total shot timing was likely at least 10 seconds. 

E2.  New evidence in Zapruder film of first shot’s timing

The “young girl” discussed in the HSCA’s Zapruder film analysis is Rosemary Willis.  Rosemary Willis was 10 years old when she witnessed President Kennedy’s murder. She can be seen in the Zapruder film running along the south side of Elm Street, in a red skirt and a white, hooded jacket.

During the first 5 seconds of the Zapruder film, Ms. Willis slows from a run, the stops abruptly. This is seen in the Gif above, slowed down a bit (0.1 frames/sec).

In the following close-up views of the Zapruder film, we can see that Ms. Willis turns her head quickly to her right, away from Kennedy and towards Oswald’s position, in frames 133 – 143.

The Zapruder film shows that Ms. Willis turns her head quickly away from Kennedy towards the Book Depository in the film’s first ½ second.  Ms. Willis then maintains her view towards the Book Depository as she slows and stops while the presidential limousine drives on past her.

Ms. Willis has explained, several times since the assassination, that she looked back at the Book Depository and stopped running because she was following the sound of the first shot.14   In an interview with Dallas Times-Herald reporter Marcia Smith-Durk, published on June 3, 1979, Ms. Willis stated:

"In that first split second, I thought it was a firecracker. But maybe within one tenth of a second, I knew it was a gunshot.;And though I don’t remember stopping and turning, I’m sure I did.  I think I probably turned to look toward the noise, toward the Book Depository."

In a Texas Monthly interview published in November 1998, Ms. Willis said:

As the motorcade made the turn from Houston to Elm Street, they'd just gone a few feet when the first shot rang out. I didn't know what it was, but I was looking for what I heard. And the pigeons immediately ascended off the roof of the school book depository building - that's what caught my eye."

Ms. Willis’ quick head turn in the first ½-second of the Zapruder to look for the source of the first shot’s noise is strong evidence that the sound of the first shot occurred at some point prior to  frame 133 and, therefore, that the first shot was fired before Zapruder began filming the assassination sequence.  This evidence has been overlooked in the same way that previous investigations gave relatively little attention to the earliest Zapruder film frames.


E2.5  Other reactions observable in early frames of the Zapruder film

In the early parts of the Zapruder film, there were a number of reactions that were happening around the same time, circa the z140's.

Click here to open a new Tab for a close-up look at early film reactions.


E3.  Application of perception-reaction time science to prevailing consensus theory

Reactions and Reaction time overview

This overview describes two primary types of human reactions pertinent to the case; involuntary reactions and voluntary reactions.

Involuntary actions/reactions and the startle reflex

Summary points from this startle reaction discussion:


An involuntary action is one which occurs without the conscious choice of an organism. If it occurs specifically in response to a stimulus, it will be known as a reflex. The reflex example of interest here is the startle reflex as a reaction to loud auditory stimuli.

In 1929 Strauss, using a revolver shot as a stimulus, isolated a definite startle behavior pattern. It was definite, symmetrical, and relatively uninfluenced by postural changes. One of its most striking characteristics was its rapidity: it might come and go within half a second.

In 1939 Landis and Hunt15, using pistol shots and high speed photography, conducted similar tests which confirmed the Strauss results. The reaction pattern included blinking of the eyes, head movement forward, a characteristic facial expression, raising and drawing forward of the shoulders, abduction of the upper arms, bending of the elbows, pronation of the lower arms, flexion of the fingers, forward movement of the trunk, contraction of the abdomen, and bending of the knees. Likewise they saw the typical response happen in about a half a second (but it could range from 0.3 to over one second depending on individuals and intensity). Landis and Hunt called the startle pattern an immediate, involuntary, and general flexion behavior.

A.N. Carlsen described the startle reflex in a thesis of “Auditory Startle Response and Reaction Time”as a generalized and diffuse protective response consisting of a characteristic set of muscle actions initiated by a sudden intense stimulus. More specifically, in response to a sudden, unexpected acoustic, tactile or vestibular stimulus, a generalized flexion response is observed in mammals. The startle response consists of a characteristic pattern of muscle flexion, as well as an increase in central nervous system and autonomic activity.

Acoustic stimuli must be adequately loud (at least 90 dB) to elicit a startle response although more intense stimuli produce larger amplitude responses and shorter response latencies.

Landis and Hunt described the startle response as a patterned response consisting of several bilateral stereotyped muscle movements. This response started with blinking of the eyes and a characteristic facial expression, along with dorsiflexion of the head and neck. The described response included a curling of the shoulders in a ventro-caudal direction, flexion of the elbows and fingers, bending of the trunk and bending of the knees. This generalized flexion response has been hypothesized by Yeomans and Frankland to be an adaptive defense response in terrestrial mammals to predatory attack from the rear, as the response results in reduced exposure of the dorsal surface of the neck, a vulnerable point of attack. Brown et al. described a similar response pattern consisting of eye closure, grimacing, as well as neck, trunk and limb flexion.

Important final points regarding startle reaction.

The definitions below are useful in understanding body movements related to joint articulation:

Flexion: Bending the joint resulting in a decrease of angle; moving the head forward at the joint just below the skull.

Rotation: Rotary movement around the longitudinal axis of the bone; turning the head to the side (right or left) at a joint below the skull.

In every study reviewed here on startle reaction, all the startle movements are classified as flexion movements. This translates to the head moving down and forward (which effectively maintains symmetry in the front/back plane going through the spine or sagittal plane). There are no studies indicating rotation (right or left) as a startle response.

Key conclusion: None of the rapid head rotations seen in the Zapruder film are startle reactions, but rather voluntary or secondary reactions of rotation.


Voluntary actions/reactions

Summary points from this voluntary reaction discussion:


Voluntary action is an anticipated, cognitive goal-orientated movement. Voluntary action is demonstrated when one cognitively identifies the desired outcome and pairs it with the action it will take to achieve it.

Voluntary reaction time can be based and tested on reacting to simple or complex stimulus scenarios.  Simple voluntary reaction time would include reacting to one stimulus and having one response (1). An example of this could be the reaction to sound with a head, hand, or foot movement. This is the simplest kind of reaction time, with little or no decision making (3) and is very relevant to the conditions encountered in the motorcade with rifle reports and subsequent reactions.

Voluntary response time, sometimes called Perception-Response Time or Perception-Reaction Time (PRT), is the lag in time between detection of an input (stimulus) and the start of initiation of a controlled response. Response time and Reaction time are sometimes used interchangeably, but typically the reaction time is the time to initiate reaction movement and response time is reaction time plus an additional short period of time for the reaction movement time (3).
Human voluntary response time is a complex dynamic and can be dependent on a number of variables. Robert Kosinski16 conducted a literature review on reaction time and the studies which looked at factors that influence reaction time. A number of factors have been studied and included variables like muscular exercise/arousal, age, gender, fatigue, alcohol, drugs, Illness, muscle tremors, previous brain injury, fasting, etc.

For the occupants of the Presidential limo and Secret Service follow up car entering Dealey Plaza, there likely wasn’t much variation from normal values for these listed variables, and over the duration of time the three shots were fired, except for JFK and Connally who had injuries, none of these factors changed.  There is however, a variable that has been shown to be a significant factor on reaction time, and would have changed over the timeframe of the assassination. Specifically this variable is “warning time” that a stimulus will occur soon. Kosinski’s references showed that that reaction times are faster when the subject has been warned that a stimulus will arrive soon, and the warning can be fast in advance. This variable has been shown significant relative to reaction time in a number of studies and can be classified as levels of “expectedness”. This variable would be important during the time of Zapruder’s filming and warrants further evaluation as the state of awareness or expectedness of shots or distress in the motorcade changed significantly and quickly as the assassination progressed.

Since expectedness of the stimulus would be the reaction time variable that changed for individuals in the assassination sequence, it would be ideal to find a study that related Perception-Reaction Time (PRT) to Stimulus Expectancy and compare that to the onset of reactions observed in the Zapruder film. Unfortunately no study controlled in exactly this way could be found. This is not a surprise as controlling an experiment with expectancy level as an independent variable may not be easy.

In an effort to extract some data on reaction time to stimulus expectancy, this author conducted a Meta-analysis on literature that had experiments on reaction time to audible stimulus, with an objective to find studies that appear to have differences in the panelist’s degree of expectancy. Reaction time studies were reviewed,  and if relevant, were classified into one of 4 groups of panelist’s stimulus expectancy (Highly Expected, Expected, Unexpected, and Complete Surprise).

These groups were classified as follows:

Highly Expected: Subjects know almost exactly when the stimulus will occur (pre-knowledge on impending stimulus timeframe: typically seconds)
Expected: Subjects know the stimulus may or will occur soon, but don’t know exactly when it will happen (pre-knowledge on impending stimulus timeframe: typically seconds-minutes)
Unexpected: Subjects know a stimulus may or will occur within an extended timeframe, but didn’t know when it would happen (pre-knowledge on impending stimulus timeframe: typically minutes-hours)
Complete Surprise: Subjects not aware a stimulus will occur (pre-knowledge on impending stimulus timeframe: unaware or long enough to essentially be forgotten)

The results of this survey are summarized on the graph below with the mean reaction time values from the studies plotted above the approximate expectedness category.

The Meta analysis result shows a range in voluntary reaction time, depending on the degree of pre-awareness, from just over 100 ms to somewhat over 1100 ms.  Perhaps not surprisingly, the greatest change in reaction time appeared to occur around the transition from an Expected to a more Unexpected state of awareness of the impending stimulus.

Voluntary reactions can occur in conjunction with startle reactions.  When both type of reactions occur, the voluntary reaction is typically called a secondary reaction as the startle reflex starts first. The voluntary secondary reactions typically begin after startle reactions have subsided, but can begin during the progression of the primary startle reactions.

Landis and Hunt classified the voluntary secondary reactions that follow a startle reaction into four categories: Curiosity, Fear, Annoyance, and Overflow effects.

Curiosity would include not only regard and attention to the stimulus source but also to other elements of the situation and even to the purpose of the experiment;  the behavior would range from turning of the head and body toward the stimulus source to a mere quizzical raising of the eyebrows.  Fear would include actual flight behavior as well as mere defensive gestures, and would cover such behaviors as running away and covering the face or ears with the hands. Annoyance would not reach the severe overt expression of anger such as attack, but there are subjects who through gestures, speech, or facial expression indicate their displeasure and irritation. The final category of Overflow effect would include all those cases where the behavior does not seem to be rational.

Notable head and body turning is seen in the early frames of the Zapruder film (see reference page on early film reactions). Additionally, displeasure and irritation may be what we see in John Connally and Jackie Kennedy's atypical facial expression after their heads have turned far left at about z161, as seen in the Croft close up photo). 

Close up of Croft photo taken about z161


Reaction Time Survey: Mean time to onset of voluntary or secondary reactions from various studies


For references on the studies where the data for this survey was gathered can be found by clicking here to open in new Tab.




E4.  Weaknesses of other support for prevailing consensus

As mentioned earlier, quite a bit of support for the standard model of the missed first shot occurring at about z157/158 is based on:

While on the surface this sequence does appear as a reasonable explanation for a z157/158 shot timing, on closer inspection, each of these points appear in error as they classify voluntary (or secondary) reactions to stimulus incorrectly by calling them involuntary startle reactions.

Let’s have a look at the weaknesses of each point.

Net, any relatively large and asymmetric motions of individuals observed in the Zapruder film that could be associated with a loud surprise stimulus are necessarily voluntary (or secondary) reactions to a stimulus and not startle reactions. In an effort to back calculate origination timing of any associated shot sound stimulus, timing for voluntary reactions are needed, not startle reaction timing.

E4i.  Camera movement analysis

In addition to the sudden camera acceleration at frame 155, another factor contributing to the mistaken perception that a shot was fired at around frames 155-157 is the fact that LIFE magazine employees accidentally destroyed frames 155 and 156 of the camera-original film, and as a result the camera-original film had a splice at frame 157.  Because frames 155 and 156 now must be supplied from copies of the camera-original film, which frame copies do not include the images in the film’s inter-sprocket area, the effect is that the Zapruder film appears to “glitch” in the vicinity of frames 155-157.  This visual artifact tends to enhance impressions that the film contains evidence of a shot at around frames 155-157.


Another look at Jiggle Analysis

“Jiggle” analysis

A number of studies have been conducted to evaluate blur/shake in the Zapruder film as an indicator of involuntary camera shake resulting from possible brief startle jiggles at the sound of gunshots. This type of analysis has been called “jiggle analysis”. Perhaps the best known study was that of Professor Luis Alvarez who published an analysis in the American Journal of Physics in 1976. Later, related analysis was conducted by two members of the Photographic Evidence Panel for the HSCA review (William Hartman and Frank Scott).  A subsequent analysis by Michael Stroscio repeated the technique of Alvarez but extended the data set to include some earlier frames (152-170) that Alvarez did not have available.




















1) The first of the graphs above represents Figure II-5 from the House Select Committee’s summary of the analysis of blurs in the Zapruder film as possible camera reflex reaction to the sound of gunshots.  This figure summarizes three related analysis of camera motion. Those three studies were:

2) The middle graph is data from Michael Stroscio's publication which extends the Alvarez data back to z152.                      

3) The lower graph is by this author and plots camera angular velocity in early parts of the film from z140 thru z272.

Since there were variations in the techniques used to measure camera motion for these graphs, the plots don’t appear identical. There are however commonalities in their results for the largest motions detected. In the early part of the Zapruder film from z140 thru ~z272, relative maximum peak swings in camera motion that line up best across all sets of graphs appear around the frames z157/158, z165/166, z184/185, z190/191, z198/199, z207/208, and z227/228. These locations are indicated by the vertical lines that spans across all sets of graphs above with a representative frame number for those locations at the bottom. 

A major question remains, “Are any of these jiggles associated with a gunshot?”.

A note about the authors bottom graph included above regarding camera angular velocity
This analysis took advantage of digital technology and looked at more recent digitized Zapruder frames (from John Costella).  Since most of the overall camera motion was included in the horizontal direction, the technique focused on camera angular velocity changes along the horizontal axis and uses pixel counts as a way to measure angles. Horizontal pixel counts from the right edge of the camera field of view to a given stationary vertical landmark (edge of Stemmons sign for example) from frame to frame was used as a measure of a camera positioning angle in each frame.  Differences in the pixel count to the fixed landmark from frame to frame are used as a measure of the change in angle for the camera over a one frame time period.  This frame to frame change in angle is the camera angular velocity in pixels per frame. (For more common units, conversion factors may be used for Zapruders camera and are estimated at 18.3 frames per second and about 62 pixels per degree from a Costella survey).
The plot above used this approach to look at early parts of the motorcade filming on the Zapruder film, and displays the raw data of camera angular velocity plotted as pixels/frame.


“Non-Jiggle” analysis

Sometimes when evaluating a problem useful insight is gained by “turning the table 180 degrees” and look at the problem from a completely different perspective.  That approach was used in this instance, and a “non-jiggle” analysis was conducted to augment the jiggle analysis. Not all camera movements, especially when panning is involved, are necessarily involuntary movements. The purpose of conducting this sort of “opposite” analysis was to look for voluntary camera movements to help sort out some of the camera motions.
In order to reduce noise in the final data series, i.e. filter out small rapid motions due to natural camera holding jitter or a potential gunshot jiggle, a smoothing algorithm was used.  A simple but effective noise reduction technique engineers sometime call a low pass filter was used which consisted of a 7 point centered moving average of the raw angular velocity data.
Natural handheld camera jiggle is estimated from studies to range from just about 3 to 10 Hz. This corresponds to a cycle Period in the range of 2-6 Zapruder frames.  Alvarez claimed from his experience a natural peak in frequency of about 3 Hz which would be about 6 frames for one shake cycle. In order to help filter out possible involuntary effects like these, a moving average of greater or equal to these periods is used.  A rolling average of 7 points (7 frames of data; averaging 3 before, the center evaluation point, and 3 after) was chosen as the averaging window since it’s the nearest odd number  >  these noise periods, but isn’t so large to over-process the data and remove voluntary trends. Recall again that we are interested in looking for conscious/voluntary movements which typically have a longer duration or period than the quick involuntary jiggle movements.
The 7 point moving average of angular velocities was plotted vs frame number to visualize the change in camera angular velocity over time once jiggle is filtered out. (see graph below with units of deg/sec)

What now appears is a smoother graph with apparent zones of low-to-no angular velocity and zones of higher angular velocity and transitions between the two. Zapruder appeared to be alternating between non-panning and panning of the camera in the early part of the film as a way to keep the limo centered in the viewfinder while it was further up the street. The graph below highlights these different zones by shading. Magenta is low to no panning and green would be active panning. The circled areas are points of approximate constant angular velocity in those zones. At the far right the circled area has a gradual increase over time as Zapruders angular velocity (panning rate) increased as the limo started to get closer and had greater tangential motion relative to him.

What’s significant in this non-jiggle graph are the areas between the circled panning and non-panning segments. These are areas of noticeable change in angular velocity vs. time and these are camera accelerations that are necessarily voluntary as Zapruder changed the camera from non-panning to panning and vise-versa. Between the circled areas, peak acceleration from changes in panning action can be seen around the transitions near where the zone colors change and correspond to frames around z157, z166, z185, z199, and z207 (note these are peak points also highlighted in the jiggle analysis except the jiggle peak around z227 has been effectively filtered out here).  A smaller adjustment in rate while panning may have occurred at z191, z215, and z231, but these are not pronounced like the panning/non-panning transitions.

The primary camera voluntary action from the non-jiggle analysis is summarized in the table below.

Frame Range

Indicated camera action




Transition to panning




Transition to non-panning




Transition to panning




Transition to non-panning




Transition to Panning



(with slight rate adjustment)



Zapruder appeared to be alternating between non-panning and panning of the camera in the early part of the film in order to keep the limo centered in the viewfinder while it was further up the street. This animation is paused at the points of active transitions from panning to non-panning and back. A good way to see the panning motion differences is to look at a stationary landmark (like the Stemmons sign).


Adding the non-jiggle analysis to the jiggle analysis indicates that the peak early Zapruder film camera accelerations are associated with voluntary camera centering motions as Zapruder transitioned from panning to non-panning and back.  Since these camera accelerations seen early in the jiggle analysis appear to be associated with voluntary camera panning actions, it follows that the jiggle analysis are not showing involuntary reactions to gun shots. Based on this extended Zapruder film analysis, no first shot is indicated in the evaluated time range from frame z140 through the time of the second shots reaction appearing in the z227 range.


E4ii.  Tree ricochet theory

Some Kennedy assassination researchers have advanced the theory that the first shot missed because it ricocheted off a branch or twig of the tree that interfered at certain times with Oswald’s view of Kennedy along Elm Street.  For these researchers, this theory lends weight to their corresponding timing of the first shot in the general vicinity of frames 155-157.

We have seen that Connally’s sudden left-then-right head turns refute the notion that the first shot was fired at around frames 155-157, since Connally’s fear-induced head turns start at frame 149, not at frame 162.  For this reason, the tree cannot be the explanation for why the first shot missed. We can see this by extrapolating JFK’s position from the following Secret Service re-enactment photograph:

which corresponds (relative to the white road stripe) roughly to Z140, which is shown below:

At this moment (approximately frame 140), which would allow for a ½ second head-turning reaction by Connally starting at frame 150, the tree is not yet a plausible cause of a ricochet.  As these two images show, not only is the tree too far ahead to cause a ricochet, it is too far to the right of the bullet path necessary to try to hit Kennedy, especially when we consider that Kennedy’s limousine was farther to the left than the car’s position in the Secret Service re-enactment.


F.    Summary of Shot Timing Analysis History

In analyzing the Zapruder film for evidence of the timing of the shots, the Warren Commission looked only at the wounding effects visible in the Zapruder film.  In its evaluation of the shot timing, CBS News examined the Zapruder film more thoroughly, looking at non-wounding effects of the shots; that is, at the shots’ effects on Zapruder.  The HSCA expanded the scope of Zapruder film analysis still further in its shot timing analysis, looking even more thoroughly at the film for non-wounding gunshot effects on people visible in Zapruder’s film.   This presentation extends the HSCA’s analysis still further by applying its analytical methods to the earliest frames of the Zapruder film, resulting in the revelation that the first shot occurred shortly before the assassination sequence commences at frame 133. 

 Slowly, almost grudgingly, the Zapruder film has revealed its obscure, yet paradoxically obvious secret: that it is only a partial record of the shooting.  Each historical advance in the thoroughness of Zapruder film analysis has moved the locus of the evidence of the first shot’s timing earlier and earlier in the film.  With each advance, the shot timing has expanded.  It is as if the Zapruder film has been telling us, more and more insistently as we have struggled to better understand it, that it’s obvious that Oswald had plenty of time – if only we would listen.  The price of understanding that truth is that we have to let go of our exceptionalist interpretations of the Zapruder film, and see it for what it is.


G.    Implications of longer shot timing

Several implications arise from this new evidence of a pre-frame 133 timing of the first shot.

First, and most importantly, the new timing strongly supports the single-gunman theory.  Even allowing for factors such as Oswald’s shooting skill, the moving target, the distances of the shots and the weapon’s accuracy, a total shot timing of 10 or more seconds makes the assassination of President Kennedy by one person highly plausible.   It effectively answers the main reason – a question of time –  for “nagging doubts” about Oswald’s sole guilt.

Second, the new timing reinforces Zapruder film’s supremacy as the best evidence of how the assassination happened.  Although we can no longer say that the Zapruder film captured the entire shooting sequence, we can say that it still provides the strongest evidence available of the time the shooting took and the sequence of events.  The prevailing consensus that the first shot occurred within the Zapruder film overlooks the best evidence:  the film itself.  The new timing hypothesis sees what is there to be seen, reaffirming the historical lesson that the key to accuracy in studying the assassination is thoroughness in studying the best evidence.

Third, the new timing reminds us of a central truth about the Kennedy assassination and, for that matter, the human experience:  that accounts of witnesses are fraught with risk of error and that physical and photographic evidence rightly take preeminence over witnesses’ beliefs, recollections and idiosyncrasies. To be sure, interpretation of physical and photographic evidence involves risk of error as well.  But in interpreting inanimate evidence we are not subject to the distorting influences of other peoples’ unjustified self-confidence, stubborn certitude and misunderstandings; we are subject only to our own pre-conceptions, biases and mistakes in reaching conclusions.  By giving the Zapruder film primacy over witness recollections and thereby reducing the sources of error, we can come closer to the truth about the Kennedy assassination.


H.    Areas for further study

Suggestions for further study prompted by the analysis set forth here include:








4 A November 29, 1963 FBI report states that the Secret Service advised the FBI “that it had been ascertained from the movie [the Zapruder film] that President Kennedy had been struck with the first and third shots fired by the assassin, while Governor Connally was struck with the second shot.”

5 No FBI or Secret Service report or statement about the re-enactment or the shot timing derived from it was released to the public or – on the record – to the press, in the first several weeks after the assassination.

6 While the Warren Commission could not rule out the possibility that the missed shot was fired after Kennedy was shot in the head, it did not consider this possibility likely – virtually every witness was certain that the head shot was the third and last shot, and Oswald had no reason to shoot again after achieving his goal.  This left the first or second shots as the most likely candidates for the shot that missed.  If the shot that wounded both Kennedy and Connally was the second one, then it followed that the first shot was the one that missed.   But the Warren Commission, Hamlet-like, could not decide.

7 Supporting evidence for the single bullet explanation included: (1) Connally’s position directly in front of Kennedy (where else could the bullet that ranged back to front through Kennedy’s neck have gone, but into Connally?); and (2) the fact that Connally’s back wound was oblong rather than circular, which implied that the bullet that struck him was tumbling due to having been destabilized by first passing through Kennedy’s neck.

8 Recall that in his first recorded statement about the shooting (the 11-27-1963 televised hospital interview) Connally said that he heard the first shot, turned to look into the back seat, observed that Kennedy “was slumped,” and then was shot himself – in that order.  However, the Zapruder film decisively refutes Connally’s recollection of the sequence of events: it shows that (a) Kennedy was not wounded by the first, missed shot; (b) that Kennedy did not “slump” because of the first shot; (c) that both Kennedy and Connally were hit by the second shot; and (d) that Connally did not turn around far enough to see Kennedy until after the second shot.  Despite the Zapruder film’s clear evidence, Connally proved inflexible in his stubborn belief that the single-bullet theory was wrong

9 In the section of its Report headed “Time Span of Shots” the Warren Commission stated, “If the second shot missed, then 4.8 to 5.6 seconds was the total time span of the shots. If either the first or third shots missed, then a minimum of 2.3 seconds (necessary to operate the rifle) must be added to the time span of the shots which hit, giving a minimum time of 7.1 to 7.9 seconds for the three shots. If more than 2.3 seconds elapsed between a shot that missed and one that hit, then the time span would be correspondingly increased.” 

10 FBI testing showed that Oswald’s rifle could be accurately fired three times within 4.6 seconds, but this was under ideal conditions by firearms experts shooting at stationary targets much closer than Oswald’s moving target.

11 One powerful illustration of the cultural forces that helped form this meme is Oliver Stone’s 1991 movie JFK, which encapsulated the “6-seconds” controversy in a scene set in 1966 in which Louisiana Senator Russell Long and New Orleans District Attorney Jim Garrison discuss the Kennedy assassination.  In the scene, Senator Long says:

"Those Warren Commission fellows were pickin' gnat shit out of pepper. No one's gonna tell me that kid did the shooting job he did from that damned bookstore. . . . Sure, three experts and not one of them could do it!   They're telling us Oswald got off three shots with world-class precision from a manual bolt-action rifle in less than six seconds -- and accordin' to his Marine buddies he got Maggie's drawers -- he wasn't any good.   Average man would be lucky to get two shots off, and I tell ya the first shot would always be the best. Here, the third shot's perfect. Don't make sense."

In this scene, Stone not only conveyed the emerging public doubt in the mid-1960s about the 6-second timing, he also perpetuated, for his 1990s audience, the myth that the Warren Commission had adopted as fact an implausibly rapid shooting scenario.  That myth hangs in the cultural air to this day.

12 shows that Connally’s jacket bulged outward at frame 224, so the second shot probably struck at about frame 222.  The third shot’s effect is obvious at frame 313.


14 For example:;

15 "The Startle Pattern"; Carney Landis & William Hunt 1939 (reprint 1968)

16 Kosinski A literature review on reaction time



Copyright acknowledgments:

·         The copyright for the Zapruder film is owned by The Sixth Floor Museum.

·         The close-up animations of Rosemary Willis in the Zapruder film were created by Gerda Dunckel.

·         The copyright for the Croft photograph is owned by Robert Croft.