Robert Hanssen, the former FBI agent turned spy the agency describes as the most damaging in its history, was found dead in his prison cell on Monday, US authorities said.
Hansen, 79 years old, He was sentenced in 2002 to life imprisonment after pleading guilty to spying for the Soviet Union and later for Russia for more than 20 years.
Prison staff began life-saving measures after finding Hanssen unconscious Monday morning, but they were unsuccessful, the Bureau of Prisons said in a statement. The cause of death was not provided.
Hanssen joined the Federal Bureau of Investigation (FBI) in 1976 and began selling classified information to the Soviet Union in 1985, according to the institution’s website.
At the time of his arrest in 2001, he had been compensated with more than $1.4 million in cash, bank funds and diamonds, in exchange for compromising numerous human sources, intelligence techniques and classified US documents, the page says. FBI internet.
FBI investigators worked for years to try to identify the spy among their ranks. In the weeks before his arrest in February 2001, some 300 staff members were involved in the investigation and were monitoring Hanssen, according to the bureau.
Hanssen was arrested after being caught exchanging classified material in a suburban Virginia park, according to the FBI.
The former agent had been serving his life sentence in a maximum security facility in Colorado.
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