1984 - KARL F. KOECHER, a former CIA employee, and his wife, were arrested 27 November as they were preparing to fly to Switzerland. At the time, he was believed to be the first foreign agent to have penetrated the CIA having operated successfully as an "illegal" for Czech intelligence for 19 years. In 1962 Koecher was trained as a foreign agent by Czech intelligence. He and his wife staged a phony defection to the US in 1965 and soon became known as an outspoken anti-Communist member of the academic community in New York City. Both became naturalized citizens in 1971 and Koecher obtained a translator job with the CIA two years later where he translated Top Secret materials until 1975. Koecher, who claimed that he was a double-agent, was arrested after being observed making frequent contact with KGB operatives. According to Federal prosecutors, Mrs. Koecher operated as a paid courier for Czech intelligence until 1983. An FBI agent testified that from February 1973 to August 1983, Karl Koecher passed on to Czech agents highly classified materials including names of CIA personnel. However the case never came to trial. On 11 February 1985, Koecher was exchanged in Berlin for Soviet dissident Anatoly Shcharansky.

New York Times, 28 Nov 1984, "Man Charged with Passing State Secrets"
                           5 Dec 1984, "Wife is Held in Contempt of Court for Refusing to Testify "
                           13 Jan 1985, "Intrigue and Countercharges Mark Case of Purported Spies"
Washington Post, 17 Apr 1988, "Moscow Mole in the CIA"