When President Kennedy's head snaps forward, Toni Foster takes one step backward.

A bullet wounding the right side of Kennedy's head would have produced spinning that is clearly absent from the Zapruder film.

Two frames of the Zapruder film show an uncharacteristic movement of President Kennedy and the eruption of tissues from the right front of his head. These frames are Z330 and Z331.

Too often people ignore blurred frames of the Zapruder film. By recognizing the characteristics of various blurs they can obtain valuable information. In fact a blur caused by a rapidly moving object conveys more information than a clear frame.

A frame-by-frame analysis of Kennedy's mechanical reactions to the fatal shot reveals details missed by viewing the motion picture.

Dr. Carrico was the first Parkland physician to examine President Kennedy.

The overlay method adjusts the position of one frame relative to another. Four buttons, Left, Right, Up and Down, enable the viewer to eliminate apparent motion caused by panning errors. Once properly aligned, successive frames show small changes in the size of objects due to their varying distances from the camera.