49 years after the assassination of President John F. Kennedy, the question that still haunts the national psyche: WHO KILLED JFK?!

For some, November 22, 1963, like December 7th, 1941 and September 11th, 2001,  is burned into the American consciousness as a "day that shall live in infamy".

On that bright day in Dallas the young President and his First Lady shone riding in a motorcade — when suddenly, shots rang out!

As Jackie barreled over the slumped body, propelled by terror — more gunfire!

Later, JFK was pronounced dead as a weeping Walter Cronkite broke the news on TV.

The official version, according to a hefty Warren Report, was that Lee Harvey Oswald, a commie sympathizer, acted "alone".

He was gunned down by Jack Ruby,  a Dallas nightclub owner with Mafia ties when Oswald was transported to jail – another event seen live by millions.

Conspiracy buffs first took note when New Orleans prosecutor Jim Garrison began to poke around into the "facts" and examined much of the evidence that was available and spoke to witnesses who were never probed by the official government investigation.

Garrison's legwork poked holed in the single-assassin belief, suggesting a conspiracy of the highest order.

Theories abounded about "exit wounds", the number of "head shots" and where the shots originated – The Texas Book Depository or from the "grassy knoll" – or both.

One theory suggested that JFK was rubbed out by the mob for turning against the syndicate after they helped the bootlegger's son "win" the election in Chicago by rigging the ballot boxes.

 New Orleans mob kingpin Carlos Marcello is said to have orchestrated the hit, noted Kennedy historian and Jackie Kennedy's first cousin, the late John H. Davis, speculated in his book Mafia Kingfish.

Others believe it was retaliation from Cuban strong man Fidel Castro as payback for the JFK-backed failed Bay of Pigs invasion led by CIA trained refugees to take the island.

More complex theories postulate that an "executive action" — the CIA working with rogue FBI agents– performed the complex logistics of assassination and cover-up under orders from a cabal of wealthy businessmen who disagreed politically with the New Frontier visionary.

President Eisenhower warned of the "industrial military complex" and there are those who have suspected the assassination of being a "coup d'etat" designed to keep the US in Viet Nam long after Kennedy wanted to withdraw US advisors. 

Sadly, we may never know for sure.

And it's the NOT knowing 49 years later that still chills the nation's soul  —  forever frozen in a single defining moment when Camelot fell.