Alexander Goldfarb was close friends with Alexander Litvinenko, a former Russian intelligence officer, who was poisoned to death in London in 2006. Two Russian intelligence operatives were behind it. But after the poisoning of Sergei Skripal, another former Russian spy, and his daughter Yulia in March of this year, Russian government-linked media outlets began accusing Goldfarb of killing his friend. Then things turned bizarre. He got a visit from the FBI and his friend's father began accusing him of killing Litvinenko. Now Goldfarb and Marina Litvinenko, the widow of Alexander Litvinenko, have decided to take action. We have exclusive details on this episode.