Aldrich Ames, a CIA officer who became one of America's most damaging double agents, has died aged 84. The former counterintelligence officer, who was serving a life sentence without the possibility of parole, died on Monday at the Federal Correctional Institution in Cumberland, Maryland, CBS News reported.

Ames was jailed on 28 April 1994 after he admitted to selling secret information to the Soviet Union and later Russia. He compromised more than 100 clandestine operations and divulged the identities of over 30 agents spying for the West, leading to the deaths of at least 10 CIA intelligence assets.

Seeking money to pay debts, Ames initiated his treachery in April 1985 by providing the KGB with the names of CIA spies, initially receiving a payment of $50,000. Known by his KGB codename Kolokol (The Bell), Ames eventually identified nearly all of the CIA's spies in the Soviet Union, earning around $2.5 million for his betrayal.

The cash fueled a lavish lifestyle, allowing Ames to purchase expensive items and enjoy foreign vacations, despite his official salary being significantly lower. He began his CIA career in 1962 after his father—a CIA analyst—helped him secure a position and went on to marry twice, first to a fellow CIA agent and later to Maria del Rosario Casas Dupuy, who was charged as his accomplice.

Ames's espionage activities continued for nine years until his arrest in 1994 amid a mole hunt. While he cooperated with authorities to secure a plea deal for his wife, the damage caused by his actions reverberated through the intelligence community. CIA director R. James Woolsey called Ames a malignant betrayer of his country, stressing how his actions led to the deaths of numerous agents.