Fact and Fiction

On November 22, 1963, JFK was assassinated and almost everyone assumed that Lee Harvey Oswald was the killer. But later, people begin to be skeptical. The new theory was that it was impossible to fire three shots (the number of shots that were in the Zapruder film) in under six seconds. However, the problem is that Oswald had approximately 8.6 seconds to fire them and in the film, Oswald actually manages to fire all three of the shots in only 5.6 seconds. This then proves this theory of why multiple shooters had to be involved incorrect.

Source:
http://www.jfk-online.com/jfk100timing.html