Tennent Bagley was working for the CIA in Switzerland in 1962 when he was sent to meet Yuri Nosenko, a KGB agent willing to betray his country from within. He seemed like a prize catch. The son of one of Stalin’s ministers, Nosenko said he could expose the Soviet spy agencies’ inner workings and name Russian agents inside Western embassies. Bagley reported back to headquarters that Nosenko had “conclusively proven his bona fides.” He came to regret that recommendation. Poring over Nosenko’s notes, Bagley noticed anomalies that led him to believe his charge was a Soviet double agent, sent to sow disinformation. Bagley would spend the next half-century trying to prove his case. “He knew what was right,” said his son, Andrew, “and he stuck to it.”
Bagley began to doubt his source’s credibility in 1964, when the KGB agent unexpectedly defected to the U.S., claiming he was under suspicion by Soviet authorities. “Nosenko came with astonishing information,” said The Daily Telegraph (U.K.). He claimed that he had interviewed Lee Harvey Oswald in the USSR before the 1963 assassination of President Kennedy and insisted “Oswald had no connection with the KGB,” said The Washington Post. It was an important assertion at a time when many officials suspected the Soviets were behind the assassination.
But Bagley and other CIA agents found problems with Nosenko’s story. At different times he said he was a colonel and a captain, and never talked about the wife and children he’d previously referred to. The Russian was thrown into “solitary confinement and subjected to various discomforts, including cold, continuous light, and periods of hunger,” said The New York Times. “Bagley questioned him again and again, harshly.” The ordeal lasted for three years, but Nosenko maintained that he was a genuine defector. The CIA later gave him $80,000, an apology, and a new identity.
Bagley never stopped trying to prove that Nosenko was a Soviet plant. After retiring from the CIA in the 1970s, he wrote several books detailing his theories. When asked in 2007 what he would say to Nosenko if they ever met in the street, he gave a simple answer: “Don’t shoot.”