being given to the zapruder film and when the president was hit first and second. >> cbs news had a tower and target track constructed to match exactly the heights and distances in dealey plaza. >> if there wasn't enough time, then you would have a second shooter. oswald was not an expert shot. he was a good shot. but making the shots was not that tough at all. cbs did it. a guy from the military did it. >> three shots he got off in 2.6 seconds. >> the zapruder film became the lens through which the assassination was seen. if it didn't happen on the zapruder film it didn't happen. zapruder started his camera after the limousine was about 70 feet into dealey plaza. well, oswald had the president in his sights for many seconds before that. and this gets into the whole questions, how much time did oswald have to shoot the