More specifically, talk about the gunshot itself and the mechanics involved in that. i know you've already touched upon mechanics of what happens when a bullet is fired from a gun, when you talked about the micro photography and that puff of gas, followed by the bullet, followed by the rest of the gas is essentially the sequence? >> yes, sir. >> so let's talk about the evidence in this case. would you describe for the jury what you saw when you looked at the photographs of the clothing that mr. martin had and the photographs of the wound to his skin and the gunshot -- or the tattoos that was r...