A little discussed connection of Note

Jack Ruby, the murderer of Lee Harvey Oswald, indeed had associations and links to repeated members of the Mafia. Yet his least known association, informant of the FBI, occurred years before he murdered Lee Harvey Oswald.
House Select Committee on Assassinations, Segregated CIA files, Jack Ruby as an FBI informant, Box 2, File 409, n.d., p. 2, 3