Robert Philip Hanssen, who received payments of $1.4 million in cash and diamonds for the information he gave the Soviet Union and Russia, has died, the Federal Bureau of Prisons announced Monday. He was 79 years old. Hanssen had been in custody at Colorado’s USP Florence ADMAX since July 17, 2002. “On Monday, June 5, 2023, at approximately 6:55 am, inmate Robert Hanssen was found unresponsive at the United States Penitentiary (USP) Florence ADMAX in Florence, Colorado,” a release from the Federal Bureau of Prisons said. “Responding staff immediately initiated life-saving measures. Staff requested emergency medical services (EMS) and life-saving efforts continued.” “Mr. Hanssen was subsequently pronounced deceased by EMS personnel,” the release said. In 2001, Hanssen pleaded guilty to 15 counts of espionage and conspiracy in exchange for the government not seeking the death penalty. He was sentenced to life in prison without possibility of parole. Investigators accused him of compromising dozens of Soviet personnel who were working for the United States, some of whom were executed. He shared details of several US technical operations such as eavesdropping, surveillance and interception of communications. And he gave the Soviets the US plans of how it would react to a Soviet nuclear attack, both in protecting top government officials and retaliating against such an attack. The \n \n Hanssen case rocked the US intelligence community, exposing major flaws in how the FBI and other agencies vet those with access to the nation’s secrets. After Hanssen’s treachery was exposed, investigators learned he had full access to the FBI and State Department’s computer systems and would spend hours trawling undetected for classified information. In his 25 years with the bureau, with access to highly sensitive sources and methods about US intelligence efforts targeting the Soviet Union and Russia, Hanssen had never been subjected to a polygraph examination. After the Hanssen case, the FBI moved to strengthen its so-called insider threat programs aimed at safeguarding the nation’s secrets by closely scrutinizing the finances and travel of personnel with access to classified information, and increasing the use of polygraphs to routinely assess employees for continued allegiance and suitability. Before Hanssen was exposed, then-FBI Director Robert Mueller said, “security was not a principle priority. There was no security division. The FBI didn’t have enough expertise. We moved to address that.” Over a decade of spying Hanssen began spying for the Soviet Union in 1979, three years after he had joined the FBI as a special agent. The counterintelligence officer worked as a spy for nearly 15 years, during some of the most consequential times for US and Russia relations and continuing past the end of the Cold War. He took a hiatus from spying for four years in the 1980s after being convinced by his wife, Bonnie. In a letter allegedly written by Hanssen to the Russians, he said that he was inspired as a teen by the memoirs of British double agent Kim Philby. “I decided on this course when I was 14 years old,” says the letter cited in the FBI’s affidavit. “I’d read Philby’s book. Now that is insane, eh!” The FBI began surveilling Hanssen in 2000 after he was identified from a fingerprint and from a tape recording supplied by a disgruntled Russian intelligence operative. After he was caught in 2001, Hanssen told his US interrogators, “I could have been a devastating spy, I think, but I didn’t want to be a devastating spy. I wanted to get a little money and get out of it.” Hanssen apologized for his actions during his sentencing in 2002. “I am shamed by it. Beyond its illegality, I have torn the trust of so many. Worse, I have opened the door for calumny against my totally innocent wife and our children. I hurt them deeply. I have hurt so many deeply,” he said. This story has been updated with additional details.