walk-in

A person who turns up at a foreign state’s mission of their own accord, to ask for political asylum or to offer to work for it from their current post.

Definition based on the International Spy Museum glossary.¹

Walk-ins can be the most valuable sources, but they also arouse suspicion that they are dangles. According to an article by B. G. Royden in Studies in Intelligence, both Colonel Oleg Penkovsky of the GRU (in 1960) and the engineer Adolf Tolkachev (in 1977) were volunteers who sought contact with Western intelligence themselves. For months Penkovsky passed letters to Western contacts before a channel was opened for him by the British businessman Greville Wynne; Tolkachev approached the CIA chief of station in Moscow, and the CIA held off replying for about a year.²

Another example: according to the FBI, CIA officer Aldrich Ames offered his services to KGB officers at the Soviet embassy in Washington of his own accord on 16 April 1985 and soon received 50,000 dollars.³