Scientists produced a sound recording of the assassination — overlooked for almost 15 years — that had been recorded at police headquarters in Dallas from a microphone thought to have belonged to a motorcycle officer who was riding in the motorcade. The recording was noisy, with static, but the scientists said that with special equipment they could identify four gunshots. Read more about the sound recording.
To the House committee, this came as a huge shock. Four shots were one more than Oswald had time to fire. "That meant there were two shooters in the plaza," said Blakey, "two shooters in the plaza equal a conspiracy."
But by synchronizing seven amateur films including the Zapruder film, Myers found that at the time of the first shot, the motorcycle was on Houston Street, about 170 feet from the position predicted by acoustic scientists, thus disproving the acoustic evidence.
Another conspiracy theory links Oswald's killer, Ruby, to the mafia, and suggests that the mafia had conspired to kill Kennedy. "I see Jack Ruby's assassination of Lee Harvey Oswald as a mob hit," Blakey told ABCNEWS.
Attorney General Robert Kennedy, the president's brother, had been leading a major offensive by the federal government against organized crime at the time of the assassination. In April 1961, Carlos Marcello, the mafia boss of New Orleans, was seized and deported to Guatemala. According to Blakey, Marcello became so angry at the Kennedy administration that he conspired to kill the president. Blakey believed Marcello recruited Oswald to shoot the president, and Ruby to make sure that Oswald never talked.
Read an interview with G. Robert Blakey, chief counsel for the House Select Committee on Assassinations.
"The theory is Ruby is taking out Oswald so Oswald can't say anything," said Ralph Salerno, who was hired by Blakey to be the committee's mob expert. "Somebody has to take out Ruby so he can't say anything. And then somebody has to take out the guy who took Ruby out. It becomes an unending dilemma so it doesn't work quite that way."
Salerno reviewed, for the committee, the electronic surveillances that the FBI had on organized crime figures all over the country, and there was no indication at all of their involvement in Kennedy's assassination.
In the Mind of Oswald
Forty years later, there has not been a single piece of credible evidence to prove a conspiracy.
Robert Dallek, author of An Unfinished Life: John F. Kennedy, says it's inconceivable that a conspiracy could have been kept secret for four decades "given a society like ours, which is so open in so many ways and so porous."
"I know that millions and millions of people in this country believe that there was a conspiracy because, I think, it's very difficult for them to accept the idea that someone as inconsequential as Oswald could have killed someone as consequential as Kennedy," said Dallek.