FBI Agent Robert Philip Hanssen is shown in this undated file photo, released by the FBI February 20, 2001.
FBI Agent-turned-traitor Robert Hanssen, who spied for the old Soviet Union and later the Russians, died Monday in the cell where he was serving 15 consecutive life sentences for betraying his country, federal prison officials said.
Hanssen, 79, was "found unresponsive" around 6:55 a.m. at the federal "Supermax" prison in Florence, Colorado, the Bureau of Prisons said in a statement.
Hanssen began spying for the Soviets in 1979, three years after he joined the FBI.
"He ultimately became the most damaging spy in Bureau history," the agency said.
Persons:
Robert Philip Hanssen, Robert Hanssen, Hanssen
Organizations:
FBI, Soviet Union, of Prisons
Locations:
Florence , Colorado, Supermax