Who is George de Mohrenschildt from Case Closed: Lee Harvey Oswald and the Assassination of JFK and what is their importance?

George de Mohrenschildt was a member of the Dallas Russian immigrant community. He was a member of the Russian nobility who held numerous university degrees. At fifty-one years of age, he was an oil geologist with business interests around the world. He was married to Jeanne and became a friend of the Oswalds.