Major Nikita Aleksandr Reznikov is the Russian father of G. Callen and Amy Callen. He was a major in the KGB but was arrested in 1974 for helping Soviet civilians escape to the West. He was sent to a gulag camp in Siberia. He later escaped and changed his name to Konstantine Chernoff. In the latest episode he finally met G. Callen and revealed to Callen his birth name, including his full first name. Grisha
