Mr. Rowland. I have been around guns quite a bit in my lifetime.
Mr. Specter. Was the sound of the fire different from the first and second sounds you described?
Mr. Rowland. No, that is just it. It did not sound as though there was any return fire in that sense.
Mr. Specter. What do you mean by return fire?
Mr. Rowland. That anyone fired back. You know, anyone in the procession such as our detectives or Secret Service men fired back at anything else. It gave the report of a rifle which most of the Secret Service men don't carry in a holster although I am sure they had some in the cars but the following two shots were the same report being of the same intensity. I state, because from a different position I know that the same rifle is not going to make the same sound in two different positions especially in a position such as it was, because of the ricocheting of sound and echo effects.
Mr. Specter. What is your basis for saying that, Mr. Rowland, that the rifle would not make the same sound in two different positions?
Mr. Rowland. This is due to a long study of sound and study of echo effects.
Mr. Specter. When had you conducted that study?
Mr. Rowland. In physics in the past 3 years.
Mr. Specter. Have you read any special books on that subject?