The first of the two head shots came from the Grassy Knoll and struck at Zapruder frame 313 causing the head to explode in what Dr. Donald Thomas has labelled a typical “Kronlein Schuss” (named for the German ballistics expert who first demonstrated the effect with clay-filled skulls). The energy deposited as the bullet passed through the brain imparted a momentum so great that a temporary cavity was formed. Consequently, a violent wave of hydraulic pressure was applied to the cranium causing it to burst open. The effect was worsened by fractures radiating from the point of entrance giving way under pressure from the brain fluid and macerated tissue, which then burst out through the upper right side of the skull. As forensic pathologist Dr. Cyril Wecht told me, the bullet that did the damage was “most likely was some kind of 'soft lead' (i.e., frangible) ammunition rather than the kind of bullet that is the 'hero' of the SBT” which was “military type ammunition that would have produced a different pattern of fragmentation and overall craniocerebral damage. According to Dr. Wecht, “A FMJ [full metal jacket] bullet should not produce” the “lead snowstorm within the brain” that is seen on the autopsy X-rays.  This “soft lead” bullet came in at a high, almost 60° angle and struck tangentially at the right temple near the hairline. Breaking up as it penetrated, it took, as objects in motion tend to do, the path of least resistance so that it was deflected upwards and leftwards; exiting high in the posterior near the midline.