Born in Czechoslovakia, he became a radio comedy writer and was allegedly frequently scrutinized by the Communist security forces for his satire that mocked the regime (this turned out to be a pre-planned "cover story"). He joined the Communist Party in 1960, and the Czechoslovak intelligence service in 1962.
Because of his English language skills, Koecher was selected to become a mole in the West. In 1965 he and his wife, Hana Koecher (the daughter of a Communist Party official), seemingly emigrated to the United States. He gained a doctorate in philosophy from Columbia University, and became an American citizen in 1971. After several years as a sleeper he was hired by the CIA as a translator/analyst in 1973 due to his fake dissident credentials and skills in a number of Eastern European languages. He was given high level security clearance and given the job of translating and analyzing documents handed over by CIA agents and transcripts of wiretaps and bugs. He quickly became one of the USSR's best sources of information, allowing them to mount an effective defense against CIA covert actions. He is believed to have betrayed Aleksandr Dmitrievich Ogorodnik, a Soviet diplomat who spied for the CIA.
In 1975, however, Koecher was summoned back to a meeting with KGB head of counter-intelligence, Oleg Kalugin. Koecher claims that after testing Koecher, Kalugin argued that he was in fact a double agent and his information could not be trusted. Koecher then retired, leaving the CIA for a post in academia. By the end of the 1970s Koecher was rehabilitated by the KGB. In 1980, with growing tensions due to the election of Ronald Reagan, Koecher was one of a number of agents reactivated. He returned to work part-time for the CIA. Although the FBI asserts that it was at that time already on to him, no action was taken against him. To this day, neither the FBI nor the CIA will reveal what alerted them to Koecher's treachery. Koecher and other KGB officials claim it was Kalugin.
The FBI apprehended Koecher and brought him and, soon afterwards, his wife in for several days of questioning. Finally, Koecher agreed to become a double agent working for the Americans, provided that they agreed to grant him immunity from prosecution. This was done and Koecher attempted to convince the FBI that he was cooperating.
However, it was then decided that Koecher was not reliable enough to be a double agent and was likely to defect and return to Czechoslovakia. On November 27, 1984, the day after the couple sold their apartment and hours before they were scheduled to fly to Switzerland, Koecher and his wife were arrested in New York City. Koecher was held on espionage charges and Hana Koecher as a material witness. The arrest of the two agents was released to the media. U.S. Attorney Rudolph Giuliani led the case.
It soon emerged that the FBI had badly blundered. Koecher's confession was given only after his interrogators promised him immunity as a ruse, and was thus invalid. His wife had been denied access to a lawyer despite frequent requests for one, which reportedly caused Justice Department officials to refuse to charge her. She refused to testify against Karl, asserting spousal privilege, though prosecutors argued this did not apply given the two had been partners in crime. With little concrete evidence, it appeared that Koecher had a good chance of being acquitted.
Koecher claims he was the victim of an attempted stabbing by an unnamed inmate while in prison. The inmate supposedly lunged at Koecher with a pair of scissors in an attack Koecher said was foiled by a Hells Angel leader in the cell next door. Koecher claims the inmate was moved to another prison, and could not be located years later, which he says is proof of an attempt by US intelligence agencies to assassinate him.
Koecher, worrying about his own safety, sent through his lawyer a request to the KGB chairman that he be part of a prisoner exchange with the Soviets. KGB chairman Kryuchkov agreed, and so did the prosecutor’s office, concerned about the embarrassing chance of an acquittal. Koecher pled guilty on charges of conspiracy to commit espionage for Czechoslovakia, and was sentenced to life in prison, which was reduced to time served provided he left the US and never returned. On February 11, 1986, Koecher and his wife were part of a nine-person exchange at Glienicke Bridge in Berlin, of which the most prominent member was noted dissident Anatoly Shcharansky.
Koecher returned to Czechoslovakia to a hero's welcome and was given a house and a Volvo car as a reward for his services. He was also given a job at the Prague Institute for Economic Forecasting, where he shared an office with Václav Klaus, the future Czech president. It is said that Koecher played an organizing role in the early days of the Velvet Revolution (1989), as he was seen by U.S. journalists issuing orders at the Laterna Magika theatre. Koecher denied any involvement in the Velvet Revolution, stating that U.S. journalists must have mixed him up with the then unknown Václav Klaus, who had a similar appearance.
The fall of communism has seen him fall from prominence, with the exception of his alleged involvement in a scheme run by self-professed former CIA operatives to defraud Mohammed Al-Fayed with false documents that would support his conspiracy theories about the death of Princess Diana. He continues to live in the Czech Republic in relative obscurity. His wife, Hana Koecher, made the headlines in the Czech Republic, when she was fired from her new job as a translator for the British Embassy in Prague. The British were completely unaware of her espionage past until a Czech newspaper reporter notified them. A suit she filed against a media organisation for revealing her past as a spy, damaging her business, was rejected.
An episode of the 2004 Canadian documentary series Betrayal! covered the Koecher case.
- Pamela Kessler (2005). Undercover Washington: where famous spies lived, worked, and loved. Capital Books. p. 27. ISBN 1-931868-97-2.
- Picking Up the Czech, Time Magazine, 10 December 1984
- "Accused spy couple awaiting trial". The Day (New London). N.Y. Times News Service. 13 January 1985. p. D-10.
- "Lawyer calls accused spy double agent". Eugene Register-Guard. 30 November 1984.
- "Czech spy to plead innocent". Prescott Daily Courier (New York). UPI. 29 November 1984. p. 2A.
- Cleveland C. Cram (October 1993), Of Moles and Molehunters: A Review of Counterintelligence Literature, 1977-92, The Center for the Study of Intelligence, p. 58
- "Wife of suspected spy not charged". The Pittsburgh Press. 29 November 1984. p. A15.
- Pete Earley (1997). Confessions of a spy:the real story of Aldrich Ames. Putnam Adult. p. 73. ISBN 0-399-14188-X. "his statement was inadmissible in court because the two FBI agents and the CIA officer who had interrogated him made promises that they never intended to keep."
- Ronald Ostrow (Los Angeles Times) (8 February 1986). "U.S. includes Czech couple in spy swap". Anchorage Daily News. p. a-8.
- Aaron Epstein (11 February 1986). "Czech Infiltrator Part Of Planned Spy Swap, A Justice Official Says". Philadelphia Inquirer.
- "East, West exchange spies, Shcharansky". Houston Chronicle. 11 February 1986. Archived from the original on 4 June 2011.
- Jeff Stein (8 July 2010). "Past Russian spies have found post-swap life gets a bit sticky". The Washington Post.
- Jan Culik (2 August 1999), Princess Diana, Al Fayed, the CIA and a Czech Spook, Central Europe Review
- Česká televize, 15. 6. 2007 Uvolněte se, prosím
- Anjali Mody (24 July 1999). "Dodi Fayed takes scriptwriters of Di's `assassination' to court". Indian Express.
- Peter Koenig (3 May 1998). "Al Fayed and the CIA conman". The Independent (London).
- Ronald Kessler: The CIA At War: Inside The Secret Campaign Against Terror, 2004, ISBN 0-312-31933-9.
- Ronald Kessler: The Bureau: The Secret History of the FBI, 2003, ISBN 0-312-98977-6.
- Ronald Kessler: The FBI: Inside the World's Most Powerful Law Enforcement Agency, 1994, ISBN 0-671-78658-X.
- Ronald Kessler: Inside the CIA, 1994, ISBN 0-671-73458-X.
- Ronald Kessler: Escape from the CIA: How the CIA Won and Lost the Most Important KGB Spy Ever to Defect to the U.S., 1991, ISBN 0-671-72664-1.
- Ronald Kessler: The Spy In The Russian Club, 1990, ISBN 978-0-684-19116-4.
- Ronald Kessler: Spy Vs Spy: Stalking Soviet Spies in America, 1988, ISBN 0-7153-9337-5.