First off, because the left would love to jump on that catchy headline, at no point on tonight's show did Glenn ever say he believed any of the conspiracy theories surrounding Kennedy. In fact, he was clear in his interview with Brad Meltzer that Oswald did it. Ok, now onto the story...

This week marks the 50th anniversary of the assassination of President John F. Kennedy. The event was not only a national tragedy, but it has famously been the source of multiple conspiracy theories that have been immortalized in modern pop culture. Was there more to JFK's assassination than has been revealed? Was there a second shooter? Was then-Vice President Lyndon Johnson a part of a massive cover up? How about the CIA?

On tonight's show, Glenn talked to two guests with two very different viewpoints on the JFK assassination.

Roger Stone wrote a book connecting LBJ to the assassination.

Stone said that on the eve of Kennedy's trip to Dallas, LBJ was facing political ruin and potential prison time. In fact, President Kennedy's secretary Evelyn Lincoln claims that JFK told her that Lyndon Johnson would not be on the ticket when he ran for reelection.

"(LBJ) was greedy, he was corrupt, he was ambitious," Stone said. "In 1963 he was a man staring into the abyss. He had two major scandals threatening his place on the ticket."

Stone, a former aide to Nixon, claims that Nixon also believed LBJ was responsible. Nixon recognized Jack Ruby, the man who killed Lee Harvey Oswald, as a man introduced to him "as one of Lyndon Johnson's boys".

"Nixon says in the Watergate tapes that the Warren Commission is the greatest hoax ever perpetrated. Nixon is in Dallas the day of the assassination, and he is actually leaving Dallas as JFK is arriving. When he gets to New York, he hears on the radio in his cab that Kennedy has been shot. When he gets to his apartment, the doorman tells him that the president is dead," Stone explains.

"He goes to his apartment. He calls J. Edgar Hoover," he continued. "So he says Edgar, was it one of those right wing kooks? 'No,' Hoover says, 'Dick, it was a communist.'"

" Well, Nixon believes that for 48 hours, until he sees Jack Ruby blow away Oswald on national television, and then he says I know that guy. In fact, we know from records that are cited in my book that Lyndon Johnson as a congressman asked Congressman Richard Nixon to hire Jack Ruby as a part-time informant for the House un-American Activities Committee, and he is introduced to Nixon in 1947 as a Johnson man, a man Lyndon would like on the payroll. So I think it speaks to why Nixon says the Warren Commission is a hoax."

Watch Stone lay out his theory below:

Glenn said he would hand off Stone's book to a friend of his who likes to uncover the truth in history and bust myths.

In the next segment, Glenn spoke with Brad Meltzer, author of History Decoded, at Dealey Plaza. Meltzer had a much different opinion about what happened that day in Dallas.

"This is literally where the seeds are planted. And we all know once you plant a seed of doubt in someone’s mind, especially America’s mind, it’s almost impossible to uproot," Meltzer said.

First off, both Glenn and Meltzer were clear in their belief that Lee Harvey Oswald was the shooter. And Glenn emphasized that all of the early reporting named Communism as Oswald's motivation.

"Let’s just put blame where it really does belong, a guy named Jack Ruby, right?" Meltzer said. "If Jack Ruby, and listen, there are questions to be asked, right? What is Oswald doing for two years in Russia that nobody knows about, two years unaccounted for? How does Jack Ruby get past an entire police station full of policeman who at that moment should be guarding this guy like he’s the ultimate person, you know, to be protected on the earth. And in that moment, Jack Ruby robbed history of the truth, because the only man who knows what’s going on is Lee Harvey Oswald."

Meltzer also said the Kennedy family's insistence of secrecy with the autopsy obscured the facts and led to the growth of conspiracy theories.

So where do all the theories of who really masterminded the assassination come from? Fear.

"It’s the big question, right? That’s the one. It’s the grand conspiracy of all. Fifty years we’ve been asking this question. What’s interesting is when you look at the 50 years of answers," Meltzer said.

"So in the 1960s, you know who we thought killed JFK? We said it was the communists. We said it was the Russians. It was the Cubans. It was our great enemy at the height of the Cold War. We also said it was the establishment. It was the 60s, distaste for the establishment. It was rich Texas millionaires who did it. They’re the ones who did him in."

"If you look historically in the 70s though, a time of Watergate and Vietnam, you know who killed JFK? It was our own government. The CIA did it."

"And now if you look in the 80s, the height of the Godfather movies and giving way to Scarface, who killed JFK? It was the mob. It was the Mafia."

"So decade by decade, if you want to know who killed JFK, it’s whoever America is most afraid of at that moment in time."