Coincidentally, a few days after JFK was ambushed on November 22, 1963, FBI Director J. Edgar Hoover sent a memorandum to the U.S. State Department regarding the JFK assassination. According to an article, "`George Bush' C.I.A. Operative" by Joseph McBride, which appeared in the July 16/23, 1988 issue of The Nation magazine, this November 29, 1963 FBI memorandum was "subject headed `Assassination of President John F. Kennedy Nov. 22, 1963" and "In it, Hoover reports that the bureau had briefed `Mr. George Bush of the Central Intelligence Agency' shortly after the assassination..."
The same Nation article also revealed that "a source with close connections to the intelligence community confirms that Bush started working for the agency in 1960 or 1961, using his oil business as a cover for clandestine activities." The Nation's intelligence community source had "worked with the agency in the late 1950s and through the 1960s" and he stated that Bush "was involved in the Caribbean" and "I know he was involved in the suppression of things after the Kennedy assassination.'"
Plausible Denial: Was The CIA Involved In The Assassination of JFK? by Mark Lane also noted that:
"There is evidence suggesting that [George] de Mohrenschildt served as a CIA control officer who directed Oswald's actions. De Mohrenschildt died from a gun shot just as he was about to be questioned by the House Select Committee on Assassinations. After his death, his personal telephone book was located. It contained this entry: `Bush, George H.W. (Poppy) 1412 W. Ohio also Zapata Petroleum Midland.'"