Mr. SPECTER. Based on the description provided to you of the nature of the wound in the Governor's back, what is your opinion as to whether, or not, that was a pristine bullet or had yaw in it, just on the basis of the nature of the wound on the Governor's back? Dr. DZIEMIAN. It could very well have yaw in it because of the rather large wound that was produced in the Governor's back. The wound from a nonyawing bullet could be considerably smaller. Mr. SPECTER. For the record, would you define in lay terms what yaw means? Dr. DZIEMIAN. It is the procession of the bullet. The bullet is wobbling on its axis, so that as it wobbles, it presents different presented areas to the target or to the air, and this changes the drag coefficient of the bullet. It will slow down the bullet more both in the air and in tissues, in the yawing. Mr. SPECTER. What is the course of a bullet, then, which is a pristine bullet or the nature of the bullet immediately after coming out of the muzzle of a rifle before it strikes anything? Dr. DZIEMIAN. A pristine bullet is normally stable. It does not wobble in the air. It presents the same presented area along most of its trajectory until it slows down, so that the drag coefficient in air or in the tissue of this type of bullet is less than the drag coefficient---- Mr. SPECTER. What do you mean by drag coefficient? Dr. DZIEMIAN. It is a measurement of the resistance of the target material or the air to the bullet. The greater the drag coefficient, the more the resistance to the bullet, the more the bullet slows down within a given time. Mr. SPECTER. So would a bullet with yaw cause a greater or lesser hole on the surface which it strikes than a bullet without yaw? Dr. DZIEMIAN. It would normally cause a greater hole. It usually would have more presented area, that is more the surface of the bullet would hit the skin. Mr. SPECTER. And would a bullet with yaw decrease in velocity to a greater, lesser, or the same extent as a bullet without yaw? Dr. DZIEMIAN. It would decrease in velocity to a greater extent. Mr. SPECTER. Whether it passed through air or---- Dr. DZIEMIAN. Or through tissue, and the important thing in tissue is that it transfers more energy to the target than would a nonyawing bullet. Mr. SPECTER. Dr. Dziemian, Governor Connally testified that he experienced the sensation of a striking blow on his back which he described as being similar to a hard punch received from a doubled-up fist. Do you have an opinion as to whether that sensation would necessarily occur immediately upon impact of a wound such as that received by Governor Connally, or could there be a delayed reaction in sensing that feeling? Dr. DZIEMIAN. I don't have too much of an opinion on that. All I can say is that some people are struck by bullets and do not even know they are hit. This happens in wartime. But I don't know about that. Mr. SPECTER. So that it is possible in some situations there is some delay in reaction?