This is the surgeon speaking about how Oswald died and the effort to save him.
He said that Oswald had zero blood pressure when he arrived. He said that the bullet tore through most of his organs (liver, spleen, pancreas, kidney, etc.) and also the aorta (largest artery in the body) and the vena cava (largest vein).
So, how was it that there was not one drop of blood at the scene?