Deciphering Kennedy's Movements
A frame-by-frame analysis of Kennedy's mechanical reactions to the fatal shot reveals details missed by viewing the motion picture.
The frames on this page are cropped to reduce vertical and horizontal panning errors. Although this adjustment enables the eye to observe otherwise obscured details, it leaves errors due to rotation of the camera unchanged. As a result we observe the illusion of a violently rocking limo.

Closer examinations of these frames reveal another illusion. Occasionally a solid object appears to change shape. A blur always accompanies this geometric distortion and suggests a localized buckling of film or other material caused the apparent change in shape.

Clicking on the Next button advances the display by one frame. The Back button switches the display to the earlier frame. By alternately clicking both buttons, subtle details of President Kennedy's motion become obvious. Two slow-motion buttons display Kennedy's movements at a Slow or Fast speed.

Although Z311 and Z312 precede the head shot, they have importance for another reason. They show all occupants moving at the same speed as the limo. This observation discredits claims that braking of the limo affected motion of its occupants immediately before the head shot.

Without doubt, Z312 and Z313 are the main events of the Zapruder film. President Kennedy was the sole occupant to show a change in position.

Alternately clicking on both links show the truer nature of the head snap. As Kennedy's head moved forward, it rotated downward. Both these motions are consistent with a force from a bullet striking the rear of his head.

However, the absence of leftward spin conflicts with the medical evidence that shows damage confined to the right side of Kennedy's head.

The dramatic movement between Z312 and Z313 vanish on Z313 and Z314. Kennedy's head appears stationary. This abrupt reduction or cessation of motion shows a second force acted on Kennedy's head about one frame after the first force set it into motion.

If spinal joints restrained farther movement of Kennedy's head then inertia would have transferred motion to his upper torso. In this case Kennedy's back would hunch forward and rotate downward with about one-fifth the speed of the head alone. Detecting such a slow movement is problematical since its duration was too brief to allow examination of following frames.

Z314 and Z315 show a rapid movement of Kennedy's head. It moved rearward and rotated upward. During this reverse head snap Kennedy's torso moved backward and rotated upward. However, the head did not move as far back as possible while the torso began its rearward motion.

The positions of Kennedy's head relative to his torso on Z315 and Z316 remained essentially unchanged. By contrast his torso rotates through a larger angle than on the Z314 and Z315.

Kennedy's head and torso continued moving as a single object on Z316 and Z317. As Kennedy rotated from a leaning toward a vertical position, gravity opposed this movement. After passing the vertical, gravity would have acted to increase the angular speed of his backward movement until the rear of the seat restrained motion.

Return to Focus on the Zapruder Film

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Last Updated on February 15, 2009 by Herbert Blenner