It was 60 years ago the world was left reeling when US President John F. Kennedy was assassinated as he travelled in an open top car with his wife Jackie on a trip to Dallas, Texas.

But ever since that fateful day on November 22, 1963, exactly what happened - and why - has been hotly debated and conspiracy theories have spun out of control.

An official 1964 investigation into who killed the 46-year-old President, titled The Warren Commission, identified 24-year-old ex-marine Oswald as Kennedy’s lone assassin but that doesn't seem to have appeased everyone, with some people instead opting to belive that Kennedy was slain as part of an elaborate plan to cover up the existence of aliens. Yes, really.

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The Daily Star asked Google Bard, the artificial intelligence chatbot, what it thought about the more out there theories and why they exist. It said that conflicting witness accounts and shady investigations inspired the madness.

"There are a number of reasons why conspiracy theories about the JFK assassination have persisted for so long. One factor is the sheer complexity of the event, with many witnesses and conflicting accounts," it said.

"Additionally, the Warren Commission's investigation was criticized for its lack of transparency and for its failure to address certain key questions."

Some of the conspiracy theories are more believable, like for example the CIA or the Cubans having a hand in it.

And Google Bard reckons that out of all the theories listed, the 'second shooter' suspicion is the most plausible.

"Several factors support the second gunman theory," it said. Firstly, the acoustic analysis of the Zapruder film, one of the most comprehensive visual records of the assassination, suggests that three shots were fired, not two as the Warren Commission concluded.

"This aligns with the testimonies of multiple witnesses who reported hearing three distinct gunshots," it added.

It added that the bullet trajectory raised suspicion, as did the presence of unidentified figures on the grassy knoll in Dealey Plaza, where the President was gunned down.

Some theories, however, are a tad more wild - and here we take a run through the weirdest of them.

A UFO cover up

An extreme conspiracy theory is that JFK was killed to stop him finding out about UFOs, having been shot 10 days after allegedly sending a secret memo to the CIA demanding to know the truth.

The top secret memo was supposedly written on November 12, 1963. In it the president ordered the CIA director to collate the agency's intelligence files relating to UFOs, and to debrief him on all "unknowns" by the following February.

Authorities were rattled, thinking that the president might have informed the American public about any alien findings, an author on the subject has claimed.

"If Kennedy had gotten some level of control of this issue from NASA or the CIA, who's to say he wouldn't have disclosed that information to the American public? Who knows where that would have led?" William Lester said.

Illuminati

It’s also been mooted that he was terminated by the ‘military industrial complex’ or a secret VIP society called the Illuminati, worried JFK would end the lucrative Vietnam War.

Another Illuminati theory is that JFK delegated presidential power to issue silver certificates to the Treasury, which threatened the power of the Illuminati-controlled Federal Reserve, the central banking system of the United States.

He in fact did the opposite, but this hasn't stopped people believing it anyway.

There have also been theories that the limo’s driver did it or a stray bullet from Secret Service agent George Hickey was the accidental cause.

His wife did it because of Marilyn Monroe affair

One of the more far-fetched theories alleges that JFK’s wife killed him herself.

Some theorists claim that Jackie Kennedy hid a pistol in a nearby flowerpot after the assassination.

But many of those who make the claim seem to overlook the fact that she was being watched in an open limousine by thousands of onlookers.

So, why would Jackie do such a thing? Well, JFK was a serial cheater according to Otto English, author of Fake Heroes.

And, of course, he had that high-profile fling with Marilyn Monroe. Theories also exist that Jackie had the actress killed, too.

He lived and fled to Cuba

The discovery of the President Kennedy film logbook has lent credence to the idea the 46-year-old may have lived.

According to the logbook: “A film was screened at the White House on November 29, 1963 for twenty people,” said conspiracy theorist Matt Novak.

White House projectionist Paul Fischer wrote it down as “Little John Birthday Party,” “presumably referring to John F. Kennedy Jr., born on November 25, 1960.”

But incredibly both President Kennedy and the First Lady Jackie Kennedy are listed as being in attendance at the screening, which took place a week after the President’s death.

“We might be able to chalk it up as Fischer being exhausted and confused or maybe it was written in advance,” says Novak.

But the meticulous nature of Fischer’s record keeping seems to suggest that would be unlikely.

“Did JFK somehow survive and live out his life under an assumed name in Cuba?” asked Novak.

“That seems unlikely, given the autopsy photos. But it probably wouldn’t be the weirdest conspiracy theory out there.”

The suggestion Kennedy moved to Cuba is coincidental considering the Cuban missile crisis played out the year before.

Soviet overlords

Lee Harvey Oswald pulled the trigger under orders from his Soviet overlords. He was a known Communist sympathiser and did defect to the Soviet Union in 1959, but changed his mind in 1961 and returned to the US.

CIA memos stemming from JFK's murder were part of a trove of nearly 1,500 documents released in December 2021 by the National Archives and Records Administration.

The documents disclose that an anonymous tipster warned US embassy officials in Australia a year earlier that Kennedy would be assassinated by the Soviet Union for a $100,000 (£79,800) bounty. The tip was never passed on to the CIA.

A memo dated 1964 read: "Cabled to Canberra asking full details of the telephone conversation of 23 November and the call made 15 October 1962.

"It should be noted that CIA had not previously known of the 1962 telephone call."

Among the revelations in the files was a meeting and follow-up phone call between Oswald and a Soviet operative before JFK was shot in Dallas.

Multiple shooters

Popularised by Oliver Stone’s 1991 movie JFK, starring Kevin Costner as DA Jim Garrison, many people believe there was more than one gunman involved.

Sceptics challenge the complex trajectory of the ‘magic bullet’, apparently found on the stretcher of wounded John Connally, the Texas governor who was seriously injured in the assassination.

Secret service agent Landis, now 88, claims he retrieved a bullet from behind JFK’s seat and put it on the president’s stretcher, reckoning it may have fallen on to Connally’s when they were side by side at the hospital.

If there was no magic bullet, was Connally hit by a different shot?

Were more bullets fired as audio evidence suggested - or from the front, not behind - as the famous Zapruder film may suggest?

Would Oswald have had enough time to fire them in a few seconds anyway?

There were also witness reports of shots fired from a grassy knoll near the murder scene. And why did Kennedy’s brain later go missing?

A 1979 House select committee determined there was probably a conspiracy to kill JFK.

Umbrella man

Witnesses at the scene have pointed a man holding a black umbrella as JFK was driven by.

This appears even more suspicious by the fact that it was a sunny day and only one man was carrying an umbrella, and was standing close to the scene when the shots were fired.

He was later identified as Louie Steven Witt. He came forward in 1978 and testified to House Select Committee on Assassinations that he was the man holding the black umbrella.

Assassination researcher Josiah 'Tink' Thompson explained: “It was a protest. A visual protest. It wasn’t a protest at any of John Kennedy’s policies as president.

"It was a protest at the appeasement policies of Joseph P. Kennedy when he ambassador to the Court of St. James in 1938 and ’39. It was a reference to Neville Chamberlain’s umbrella [and the prime minister’s appeasement of Hitler and the Nazis].

“I read that, and I thought: ‘This is just wacky enough – it just has to be true.' And I take it to be true,” Thompson said.

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