Robert Hanssen: who was FBI agent, was he a Russian spy, Breach operation explained - is cause of death known?

Robert Hanssen, a former FBI agent who infamously operated as a Russian mole and is recognised as one of the most destructive spies in American history, has been found dead in the high-security prison where he was being held in Florence, Colorado.

At the age of 79, Hanssen had accumulated a staggering sum of more than $1.4 million in cash, diamonds and funds deposited into Russian bank accounts as compensation for his treasonous activities. The case against him involved the dedicated efforts of 300 agents, highlighting the gravity of his betrayal and the extensive resources deployed to bring him to justice.

In 2002, Hanssen was handed a life sentence for his espionage activities, marking the severe consequences of his actions and the significant threat he posed to national security. But who was Hanssen, what was his story and how did he die? Here is everything you need to know about him.

Who was Robert Hanssen?

Robert Hanssen is an infamous figure in the history of espionage, known for his betrayal of the United States as a longtime FBI agent turned Soviet and Russian spy.

Born in 1944, in Chicago, Illinois, Hanssen initially seemed like an unlikely candidate for treason - he grew up in a strict Catholic family, served as an altar boy, and even attended a Catholic seminary for a brief period. But beneath this seemingly ordinary exterior, Hanssen harboured a complex and treacherous secret life.

Hanssen joined the Federal Bureau of Investigation in 1976, where he began his ascent through the ranks. His intelligence and technical skills earned him a reputation as a talented agent specialising in counterintelligence and computer systems.

His work involved investigating Soviet espionage activities during the height of the Cold War, giving him unparalleled access to highly sensitive information.

In 1979, Hanssen made his first contact with the Soviet Union's intelligence agency, the KGB. He began providing them with classified documents and other valuable information. Over the next two decades, he betrayed his country repeatedly, selling secrets that compromised national security and jeopardised the lives of American agents and assets.

What made Hanssen particularly dangerous was his ability to avoid detection. He implemented sophisticated techniques to communicate with his Russian handlers, using encrypted messages and dead drops. His activities were meticulously planned and executed, making it incredibly difficult for the FBI to uncover his double life.

Hanssen's treachery came to an end in 2001 when an FBI investigation, codenamed "Breach," finally exposed him. The FBI had enlisted the help of former KGB officer and defector, Oleg Kalugin, who confirmed Hanssen's identity as a spy. Hanssen's arrest in February 2001, sent shockwaves through the intelligence community and the American public.

During his trial, it was revealed that Hanssen had compromised an extensive amount of classified information, including the identities of several double agents working for the United States, and his actions directly led to the execution of at least two Russian informants.

In exchange for the information he provided, Hanssen received substantial financial compensation from the Russians, amassing a significant fortune over the years. In June 2002, Hanssen pleaded guilty to espionage charges and was sentenced to life in prison without the possibility of parole.

His betrayal marked one of the most devastating breaches in American intelligence history, highlighting the vulnerabilities within even the most trusted institutions. His case prompted significant reforms within the FBI and other intelligence agencies, aiming to prevent similar betrayals in the future.

How did he die?

Hanssen's body was found on Monday morning (5 June) at a maximum-security facility situated in Florence, Colorado.

The exact cause of Hanssen's death remains unconfirmed at this time, further investigations are underway to determine the circumstances surrounding his passing. ADX Florence stands as one of the most impregnable federal prisons in the United States.

The fortified institution also houses other notorious inmates of high-profile significance, such as Zacarias Moussaoui, a member of the terrorist organisation al-Qaeda, and Dzhokhar Tsarnaev, the perpetrator of the infamous Boston Marathon bombing.