Elements of the CIA did it—with an assist from LBJ and J Edgar Hoover and the Mob.
It was a real coup.
Reading materials:
https://www.amazon.com/Bond-Secrecy-Watergate-Conspirator-Howard/dp/1936296837
https://www.amazon.com/Man-Who-Killed-Kennedy-Against/dp/1629144894
Trumps was bloodless,
So far.
The CIA will not allow anything to expose their dirty deeds against the USA. They are the worst agency ever created by the US government. They smugly think they are patriots who know better but in reality they are a government crime syndicate enriching themselves at America’s expense. The DOJ/FBI are amateur’s compared to the CIA when it comes to screwing over the USA.
I would have never thought this thirty years ago, but from 1989 to now their behavior has been exposed more and more and they are incompetent, corrupt and authoritarian.
I know who it was. And yes the last entity you mentioned was involved.