FBI Man Hunt: Spent Decades Hunting for a Soviet Spy on Its Staff

One spring night in 1962 a short, stocky Russian walked into the FBI office in Midtown Manhattan and offered his services as a spy for the United States. Aleksei Kulak, then 39, was working undercover as a science official at the United Nations. He said he was unhappy with his progress at his true employer, the KGB. A tip provided by a double-agent for the KGB set off one of the most…