Has murder become an accepted political tool?

The history of the planet involves the overthrow of one leader by another for sole purpose of power. We in the west have been led to believe what we are told. We do not examine in detail what we need to know. I know for example without going to wickipedia and off the top of my head that John Wilkes Booth Shot Abe Lincoln in Fords Theater, I don’t know why. But I accept that it happened.
I know that JFK was shot in Dealy plaza by a gun man apprehended that day in a theater Lee Harvey Oswald was later shot while in custody by Jack Ruby a man with known mob ties. How do I know this I saw it on TV. That’s what I saw, but why it happened that way was poorly explained, and became one of the biggest cover ups in American history. I know that Bobby Kennedy was murdered and that some guy with the unlikely name Sirhan Sirhan was arrested and charged and convicted. I saw that on TV as well but I don’t know why he did it the reasons given at the time didn’t make sense. Dr. Martin Luther King was gunned down but I don’t remember who did it, but I do remember at the time thinking this happened because he was a very well spoken black man that was in the face of the establishment, that was a word during the sixties that meant something and I did know what that was. And I believed then and now that was true. Malcolm X was a black radical I was told and he to bought a bullet. There was a lot of establishment clean up going around in the sixties. It was only fashionable in some circles but widely accepted as fact by the majority. Moving forward and forgive me if I have failed to report or missed any other unfortunate and untimely demises.
Let us skip directly to the undetermined and untimely death of the third Kennedy John Jr. The beginning of a new methodology the small plane crash was soon to over throw the bullet. I know off the top of my head that his plane and remains were recovered and pilot error was assumed to be the cause. End of story nothing to see here so we will move along what could he have possibly been up to except being a Kennedy with possible future political persuasions. Next in line and the forerunner of future icing on the wings for politically fortuitous considerations. Paul Wellstone had actually read the patriot act before it was enacted and was against it, he was also poised to speak out against it, and down he goes along with several others. The last on my list of politically expedient demises was most recently the unfortunate plane crash of Mike Connell. This man was the internet guru used by the White House during the 2004 election cycle and man responsible for archiving White house emails he was purported to have been threatened by Karl Rove and poised to testify about alleged impropriety.
Murder most assured with Lincoln, JFK, and Bobby Kennedy. Martin Luther King and Malcolm X. The politically fortuitous death of these others I leave up to too you to decide were they murder or just ??