Conspiracy buffs blame conspiracies on people they do not like. Liberal conspiracy buffs blame the assassination of John Kennedy on the CIA, the Pentagon, or an organization like that. They do not blame the American Communist Party, even though Lee Harvey Oswald was a Communist sympathizer.
Actual conspiracies usually involve small numbers of people and do not last very long. I have difficulty believing in a conspiracy involving large numbers of people and lasting for a long time. Someone will talk.
The Manhattan Project to develop the atomic bomb involved a lot of people, but it only lasted a few years.
The Tuskegee syphilis experiment lasted forty years, but it only involved a fairly small number of people. Eventually it was exposed by someone who was part of it.
The Manhattan Project and the Tuskegee syphilis experiment are the only examples I can think of of conspiracies involving large numbers of people, or lasting for a long time.
I have two conspiracy theories about the death of Kennedy, but they involve small numbers of conspirators. I am not claiming that either happened, only that they may have happened.
In the early 1960s the CIA made a number of attempts to assassinate Fidel Castro. Several KGB officers assigned to the protection of Castro may have decided to hit back. This would not have been a conspiracy by the entire KGB, only by rouge officers acting on their own.
During the election of 1960, Joseph P. Kennedy paid Mafia gangsters to stuff ballot boxes in tight election districts. John Kennedy did not learn about this until after the election. He asked Richard Nixon if he intended to order an investigation. Nixon said that would be bad for the country.
As president John Kennedy appointed his brother Robert to be Attorney General. Robert Kennedy began to go after the Mafia. Gangsters hired by Joseph P. may have felt betrayed, and hit back by orchestrating the death of Kennedy.
If either of these conspiracies happened, Oswald was part of them. The evidence against him was overwhelming.
I don’t think either happened. I think Oswald operated on his own. From what I know of the assassination of Kennedy I do not know of anything Oswald could not have done on his own.
I think James Earl Ray may have had help killing Martin Luther King. Ray was a petty criminal who lived a hand to mouth existence, and did not seem to be very smart. Immediately after killing King he managed to get a false passport, travel to Canada, and from there fly to Great Britain where he was arrested. Doing this required more money and expertise than he seems to have had.
In the case of Ray it is easy to think of right wing fat cats who would have financed him.