Who is Franco Piccioni / Frankie Pigeon from The Tears of Autumn and what is their importance?

Franco Piccioni / Frankie Pigeon is a member of the Chicago Mafia, Pigeon hires Jack Ruby to execute accused Presidential assassin Lee Harvey Oswald in November 1963 as an act of patriotism. Gherman Klimenko, in the U.S. as a TASS correspondent assigned to the U.N. in 1956 approached Pigeon, claiming to the a Belgian businessman. He gives him a $100,000 retainer and sets ups a safe meeting house, should the Belgians ever need his service. Klimenko, of course, works for the KGB. In November 1963, Klimenko deposits $1 million in a numbered Swiss bank account after Ruby completes his mission.