Professor Larry Sabato has published new evidence in his book, “The Kennedy Half-Century,” suggesting Lee Harvey Oswald worked alone in the JFK assassination.

The 1964 Warren Report, which was the first official inquiry into the president’s assassination, stated that there was no evidence Oswald worked with anyone, but conspiracy theories continued and seemed to receive confirmation when the House Select Committee of Assassinations stated that Kennedy was “probably assassinated as the result of a conspiracy” in 1979. This statement relied on an audio recording in which four gunshots are heard coming from two different locations including the famous ‘grassy knoll’ located ahead of the president’s car.

Sabato, who is the director for the Center for Politics at the University of Virginia, said on "CBS This Morning" that his book will blow the House Select Committee “out of the water.” He had the tapes re-analyzed using new available technology and he argues the sounds long understood as gun shots are actually an idling motor cycle and a rattling microphone. He also says that the police transmissions actually come from two miles away and not Dealey Plaza where Kennedy was shot.

Sabato believes that the Warren commission was deeply flawed. He argues that they did not pursue hot trails and interview the right people when they had the chance. Sabato added that investigators were pressured to report quickly and the correct conclusions they reached were by chance.

Likewise he finds flaws with the House Select Committee. CBS News quoted him, “Their evidence simply does not hold. And they concluded there was a conspiracy. Does it mean that no one encouraged Oswald or that Oswald had no compatriots working with him? I can’t say that for sure because the Warren Commission was also deeply flawed. They made so many mistakes in their process, they didn’t interview key witnesses that I interviewed 50 years after the assassination and I was stunned to find out they weren’t part of that study.”

Popular conspiracy theories suggest that Oswald’s co-conspirators included the Cuban government, organized crime groups, and the CIA. Sabato says he’ll believe anything, but in the end there has to be proof that could stand up in a courtroom.

Despite his work, Sabato still argues that the Kennedy assassination will remain a mystery. “If we can go 100 years into the future, I guarantee you whatever replaces television, there will be new documentaries proposing new theories about the Kennedy assassination.”

Kennedy was assassinated by Oswald on November 22, 1963 during a visit to Dallas. Oswald was killed by Jack Ruby two days later, long before he could stand trial.

Footage from the documentary "The Kennedy Half-Century”, basked on the book by Professor Larry Sabato: