[6][7] Joannides directed and financed Directorio Revolucionario Estudantil (DRE), or Student Revolutionary Directorate, a group of Cuban exiles whose officers had contact with Lee Harvey Oswald in the months before the assassination of President John F. Kennedy on November 22, 1963.

[1] In 1978 the CIA summoned Joannides to serve as the agency's liaison to the United States House Select Committee on Assassinations (HSCA), in specific regard to the death of President Kennedy.

Washington Post reporter Jefferson Morley wrote that, "the spy withheld information about his own actions in 1963 from the congressional investigators he was supposed to be assisting.

[14] In 2013, John R. Tunheim and Thomas E. Samoluk wrote in the Boston Herald: There is a body of documents that the CIA is still protecting, which should be released.

In his later years, Joannides had heart problems and moved to Houston, Texas to receive medical treatment from Michael DeBakey.