The Mafia ran a lot of Casinos in Cuba until Castro kicked them out.

Many suspected the involvement of the Mafia when the President was assassinated on November 22. Suspicions increased two days later when accused Kennedy assassin Lee Harvey Oswald, then in the custody of the Dallas Police, was shot and mortally wounded in front of TV cameras by local nightclub owner and Mob associate Jack Ruby.

On 17th November, 1963, mobster Lewis McWillie (who had earlier run Mafia casinos in Cuba) was seen with Jack Ruby at the Thunderbird Casino Las Vegas. Two days after meeting McWillie in Las Vegas, Ruby was back in Dallas with enough cash to pay off all his debts. Three days later the President was dead and 5 days later Oswald was dead.

What does all that mean? I have no idea but I wish I was a history major that needed a thesis topic so I could find more out.