Robert Hanson, 79, the Russian mole turned FBI agent notorious as one of the most damaging spies in American history, has died in prison.
He was unresponsive Monday morning at a maximum security facility in Florence, Colorado.
Hanson received more than $1.4m in cash, diamonds and payments into Russian accounts. Three hundred agents worked on his case.
He was sentenced to life imprisonment in 2002 for espionage.
Hansen at the time lived with his wife and six children in a modest four-bedroom house in suburban Virginia.
Because of his counterintelligence role, he had access to classified information and in 1985 he began his criminal activities, sending material to Russia and the former Soviet Union.
Hanson, who became an FBI agent on January 12, 1976, used the alias “Ramon Garcia” when communicating with his handlers.
According to the FBI’s website, he “compromised numerous human resources, counterintelligence techniques, investigations, dozens of US government documents, and extraordinarily important and valuable technical operations”.
Although suspicions arose from time to time about his unorthodox activities, he remained undetected for many years.
After spy Aldrich Hazen Ames was arrested by the FBI in 1994, the bureau realized that classified information was still being leaked, prompting Hansen’s investigation.
He was about to retire, so the FBI moved quickly to catch him “red-handed.”
“What we wanted to do was get enough evidence to convict him, and the ultimate goal was to catch him in the act,” said Debra Evans Smith, former deputy assistant director of the counterintelligence division.
He is given a bogus mission to take him back to FBI headquarters for close surveillance.
Hansen began working in his new office at FBI headquarters in January 2001 — complete with hidden cameras and microphones.
A month later, investigators learned he was planning a dead drop at a park.
According to the Central Intelligence Agency, a dead trap is when one person leaves items for another person at a predetermined location.