Robert Hanssen, a former FBI agent who spied for Moscow for more than two decades during and after the Cold War in one of the most damaging espionage cases in U.S. history, died in a Florence, Colo., federal prison at 79. Hanssen’s case was one of the most notorious spy scandals of his generation, shocking FBI leaders and other government officials when they learned that one of their own had been feeding information to the other side for many years. The FBI describes him as “the most damaging spy in bureau history.,” reports the New York Times. In exchange for $1.4 million in cash, bank funds and diamonds, Hanssen passed along secrets to Moscow, including one disclosing that the U.S. dug a tunnel underneath the Soviet embassy in Washington, D.C., to eavesdrop on diplomatic and other communications. He informed Moscow about three K.G.B. officers who were secretly spying for the U.S., two of whom were executed.
“The magnitude of Hanssen’s crimes cannot be overstated,” said former U.S. Attorney Paul McNulty, who prosecuted him. “They will long be remembered as being among the most egregious betrayals of trust in U.S. history. It was both a low point and an investigative success for the FBI.” Hanssen’s arrest in 2001 briefly harmed U.S.-Russian relations at a time when the former enemies were seeking to build friendlier ties after the collapse of the Soviet Union. President George W. Bush expelled 50 Russian diplomats, and President Vladimir Putin of Russia retaliated with an expulsion of 50 U.S. diplomats. The discovery of Hanssen’s espionage embarrassed the FBI and resulted in changes to security procedures. He told investigators after his arrest that FBI security was so lax that it amounted to “criminal negligence.” He said it was a simple matter to gain access to classified material on official computers with routine security clearances. Hanssen pleaded guilty to 15 counts of espionage and conspiracy to avoid the death penalty. “I am shamed by it,” he said at the 2002 hearing where he was sentenced to life in prison without parole.