The conclusion of Bond of Secrecy My Life with CIA Spy and
Watergate Conspirator E. Howard Hunt by Saint John Hunt.

..Hunt went on to add, “The person who had the most to gain from Kennedy’s assassination was LBJ. There was nobody with the leverage that LBJ had, no competitor at all. He was the vice president, and if he wanted to get rid of the president, he had the ability to do so by corrupting different people in the CIA. It has also been said by many LBJ biographers, such as Robert Caro in The Path to Power, that the man idolized money, was corrupt and unprincipled, with unlimited ambition – not the type of individual who was content to end his career as vice president … Many people conjecture that Johnson was set to drop even lower in footnote status, observing that he was set to be cut from the 1964 presidential ticket. He and Kennedy did not get along, and theirs was purely a marriage of convenience …”

Hunt concluded that, “Having Kennedy liquidated, thus elevating himself to the presidency without having to work for it himself, could have been a very tempting and logical move on Johnson’s part. It wouldn’t have been hard for him to make contact with Harvey, another ruthless man who was not satisfied with his position in the CIA and its government salary. He definitely had dreams of becoming DCI, and LBJ could do that for him if he were president. If LBJ had anything to do with the operation, he would have used Harvey, because he was available and corrupt. LBJ had the money and the connections to manipulate the scenario in Dallas and is on record as having convinced JFK to make the appearance in the first place.” Of course, we know that LBJ did not make Harvey the DCI [head of the CIA], but rather put Richard Helms into this position – perhaps another indication that Helms was a key figure in the plot.

full text here
https://exploringrealhistory.blogspot.com/2023/01/part-4-of-4-bond-of-secrecy-my-life.html