I think both the Kennedy's were killed by members of organized crime. The more important question is why were they Killed? There are some clues that need to be considered.
In 1908, Congress passed the Aldrich-Vreeland Act. It authorized national banks to issue emergency currency. It also created the National Monetary Commission, whose task it was to develop a plan to deal with the periodic financial crises.
The Taft Administration (1909-1913)
In November 1910, a small group of international bankers, together with Senator Nelson Aldrich and Asst. Secretary of the Treasury A. Piatt Andrew met in a very secret meeting at J.P. Morgan's Jekyll Island Hunt Club, a private island preserve off Brunswick, Georgia, for the purpose of planning a private banking cartel in America similar to the ones in Europe controlled by the bankers. This soon became the Federal Reserve System. Baron Alfred Rothschild was the mastermind behind the plan. Paul Warburg, a partner in Kuhn, Loeb & Company, was Rothschild's representative at the meeting. A fascinating picture of this important cabal is presented in G. Edward Griffin's book, The Creature From Jekyll Island, which is also one of the best books available to explain money and banking in a clear and entertaining fashion
for a privately-owned banking system, the challenge was to figure out a way to get the U.S. Congress to approve it. Teddy Roosevelt, a Republican, was fairly popular with the voters, seemed likely to be reelected, and was considered highly unlikely to support the bankers' plan. His Democratic opponent, Woodrow Wilson, under the strong influence of Rothschild agent ``Colonel'' Edward Mandel House, was much more agreeable to the globalist agenda. So the conspirators persuaded Republican Teddy Roosevelt to run on the Progressive Party (Bull Moose) ticket, giving him considerable financial support. As a result of the splitting of the Republican vote, Democrat Woodrow Wilson was elected President.
The Wilson Fiasco (1913-1921)
The election of globalist puppet Woodrow Wilson paved the way for three major abominations: The Income Tax, the Federal Reserve System and World War I.
In 1913, the Sixteenth Amendment to the Constitution was supposedly adopted. This amendment is known as the income tax amendment. Actually, it did not repeal the existing constitutional provisions relating to taxes and thus created no new taxing powers. Furthermore, as proved by the exhaustive research of Bill Benson and Red Beckman, the alleged amendment was not properly approved by any of the 48 states then in existence, much less than by the required three-fourths of them, so the Sixteenth Amendment was never ratified. Their book, The Law That Never Was, gives the details of their findings. The bottom line is that the income tax has been a massive fraud from the outset, totally lacking in a legal basis.
Also in 1913, the Federal Reserve Act was passed. The final vote occurred in the U.S. Senate on December 22, when most members of Congress were home for Christmas and only five selected senators were present at an evening session. This act created a private banking cartel entirely owned by the bankers which allows them to create money out of thin air, to expand it further by means of fractional reserve banking and to totally control our economy. The only connection to our government is that the President nominally appoints members to the Federal Reserve Board for 14-year terms but in practice the bankers' candidates have always been appointed. Paul Warburg, a German national, and one of the Jekyll Island conspirators, became the first Chairman of the Federal Reserve Board in 1914. His brother Max was financing Germany's involvement in World War I at the same time.
All wars in modern times have been instigated by the greed of the international bankers (who lend vast sums of money at usurious interest rates to governments) and the international businessmen (who profit handsomely from the sale of war material). World War I was no exception. The assassination of Austrian Archduke Franz Ferdinand in Serbia on June 23, 1914, was the excuse for war in Europe.
The Kennedy's were very rich, but they were not globalist. I believe that was the reason for murdering them.