Before she became one of the CIA’s most celebrated mole hunters, Sandra Grimes was ready to slow down. In 1991, after more than two decades with the agency, Grimes was contemplating a quieter life, hoping to spend more time with her family. “I was not old enough at the time to retire,” she recalled in an interview for the National Security Archive at George Washington University, “but I was satisfied professionally. I had a family that I wanted to spend more time with.”
But fate—and history—had other plans. That year, the CIA faced a disturbing mystery: a string of its informants in the Soviet Union had “gone dark” in the mid-1980s. The phrase, chilling in the world of espionage, meant that agents had vanished, presumably identified, interrogated, and, in many cases, executed. The loss was not just operational—it was deeply personal for Grimes. “It was a terrible, terrible reminder of the seriousness of what we did for a living,” she reflected. “We owed all these people who had made the sacrifice.”
Grimes agreed to stay on, joining a small, determined group of colleagues investigating what had gone wrong. Their probe would ultimately expose one of the most damaging betrayals in American intelligence history. According to the National Security Archive, their work centered on Aldrich Ames, the CIA’s counterintelligence chief for Soviet operations—a man Grimes and others knew simply as “Rick.”
Ames, on paper, seemed an unlikely traitor. Yet as Grimes and her team dug deeper, the evidence mounted. Ames’s personal life was marked by episodes of public drunkenness, a string of affairs (one of which triggered an expensive divorce), and a subsequent marriage to a former informant. But it was his sudden, inexplicable wealth that raised the most red flags. He began wearing tailored suits, capped his teeth, paid cash for a new house, and drove a Jaguar—all on a civil servant’s salary. The numbers simply didn’t add up.
Grimes’s meticulous nature served her well. She pored over activity logs and financial statements, searching for patterns. What she found was damning: on three separate occasions, after Ames had lunch with a Soviet embassy official in Washington, D.C., he deposited thousands of dollars into his bank account. “Well, three matches don’t make a conviction, but in my mind, Rick was the spy,” Grimes remembered. “It didn’t take a rocket scientist to add one plus one plus one.”
Her instincts were right. The investigation culminated in 1994 when Aldrich Ames was arrested and ultimately pled guilty to espionage. He had taken millions of dollars for his work as a Soviet mole—payments that had cost the lives of numerous CIA informants and crippled American operations in the USSR. Ames is still serving a life sentence for his crimes.
The impact of Ames’s betrayal cannot be overstated. As the Senate Intelligence Committee would later declare, Ames “caused more damage to the national security of the United States than any spy in the history of the CIA.” The loss of so many informants, and the chilling effect on future intelligence work, left scars that would linger for decades. Yet, as NBC News reported, it was Sandra Grimes’s relentless pursuit of the truth that brought Ames to justice and helped the agency begin to heal.
Grimes’s journey to that pivotal moment began long before the Ames case. She joined the CIA in the late 1960s, a time when women were still a rarity in the upper ranks of American intelligence. Over her career, she built a reputation for analytical rigor and quiet determination. Colleagues described her as unflappable—a trait that served her well in the high-stakes, high-pressure world of espionage. Her ability to connect dots that others missed, and her willingness to question even the most established figures, made her a formidable investigator.
Her partnership with fellow CIA officer Jeanne Vertefeuille was particularly significant. Together, they formed a close-knit team that methodically unraveled the mystery behind the agency’s catastrophic losses in the Soviet Union. Their work, conducted in the shadows and often under immense pressure, became a model for counterintelligence investigations. According to the National Security Archive, Grimes’s approach was characterized by “dogged persistence and a refusal to accept easy answers.”
Even after Ames’s arrest, Grimes remained acutely aware of the human cost of espionage. In her interviews and later writings, she spoke movingly about the informants who had risked—and often lost—their lives. “We owed all these people who had made the sacrifice,” she said, underscoring the profound sense of responsibility that drove her work. For Grimes, the pursuit of justice was never just about catching the mole; it was about honoring the memory of those who had trusted the CIA with their lives.
Grimes retired from the CIA after a distinguished career, but her legacy continued to resonate within the intelligence community. She co-authored a book with Vertefeuille, sharing the inside story of their investigation and offering rare insights into the world of counterintelligence. The case has since become a staple in intelligence training, a cautionary tale about the dangers of complacency and the necessity of vigilance.
Her story also found its way into popular culture, inspiring documentaries and dramatizations that brought the high-stakes world of Cold War espionage to a wider audience. Yet those who knew her best remember Grimes not as a celebrity, but as a dedicated public servant who never lost sight of the people behind the headlines.
Sandra Grimes passed away on July 25, 2025, at the age of 79. Her death was noted by major news outlets, including NBC News, which described her as a “CIA ‘Mole Hunter’” whose work was crucial in identifying and stopping Aldrich Ames. The timing of her passing serves as a reminder of the era she helped define—a period marked by secrecy, sacrifice, and, ultimately, justice.
In the end, Sandra Grimes’s legacy is one of quiet heroism. She stayed on the job when it would have been easier to leave, followed the evidence even when it pointed to a trusted colleague, and never forgot the human cost of betrayal. The intelligence community, and the country, owe her a debt that can never truly be repaid.
