However, the most reliable information concerning the period Oswald spent in Moscow in the latter part of 1962 comes from the records of the American Embassy in Moscow,[C6-138] the testimony of Embassy officials,[C6-139] and the notes of two American newspaper reporters, Aline Mosby [C6-140] and Priscilla Johnson,[C6-141] who interviewed Oswald during this period. Oswald’s correspondence with his brother and mother has also been relied upon for some relatively minor information. The findings upon which the Commission based its conclusion concerning Soviet involvements in the assassination were supported by evidence other than material provided by the Soviet Union[C6-142] or Oswald’s writings. The Central Intelligence Agency has also contributed data on the normal practices and procedures of the Soviet authorities in handling American defectors. The “Historic Diary” indicates that on October 16, 1959, the day Oswald arrived in Moscow, he told his Intourist guide, Rima Shirokova, that he wished to renounce his American citizenship and become a Soviet citizen. The same day, the guide reportedly helped Oswald prepare a letter to the Soviet authorities requesting citizenship.[C6-143] The diary indicates, however, that on October 21 he was informed that his visa had expired and that he would be required to leave Moscow within 2 hours.[C6-144] During the preceding days, according to the diary, he had been interviewed once and perhaps twice by Soviet officials.[C6-145] During this period the KGB,[B] the agency with primary responsibility for examining defectors arriving in Russia, undoubtedly investigated Oswald as fully as possible. In 1959, virtually all Intourist guides were KGB informants, and there is no reason to believe that this was not true of Oswald’s guide.[C6-146] [B] The Committee for State Security, best known by its Russian initials, “KGB,” is a lineal descendant of the revolutionary ChEKA and has passed through numerous changes of name since 1917 with little change of function. Presently the KGB handles all Soviet counterintelligence operations and is the instrument for various types of subversive activities. It is responsible for the internal security of the Soviet state and the safety of its leaders. In addition it shares responsibility for foreign espionage activities with the intelligence component of the Ministry of Defense, the “GRU.” The KGB would have the primary responsibility for keeping track of a defector such as Oswald.