In order to distance himself from the activities swirling around him, Ames requested a transfer to the office in Rome, Italy. While assigned there, he and his wife began spending lavishly on clothing and accessories. Ames also purchased a Jaguar.
In November 1986, the CIA assigned 32 year employee Jeanne Vertefeuille to help isolation the source of the information flow. She and her small group of analysts focused on known traitors such as former Marine guard Clayton Lonetree, but realized that none of these people possessed the scope of knowledge apparent for the breach.
In 1987, Dan Payne, a young investigator with knowledge in accounting was assigned to her group and decided to look for a money trail to lead him to the mole. Payne began looking into the spending habits of various CIA personnel. When the Ames' moved back to the United States, they purchased an expensive house and Rosario announced to friends that she intended to add new drapes to the entire house. Knowing how expensive this would be, one of the Ames' friends, Diana Worthen, informed one of the mole hunter (Sandy Grimes), of the Ames' sudden wealth. Grimes began researching Aldrich's past dealing with the Soviets while Payne began digging through the Ames financial records and found that the couple was spending up to $30,000.00 each month, while Aldrich's annual salary was less than $70,000.00. Further investigation, however, led the CIA to believe that Rosario's family was considerably wealthy and that this was the source of the Ames' new finances.
Undeterred, Grimes continued investigating and noticed that there was a co-relation between the dates of Ames meetings with Chuvakhin and his bank deposits. With this information in hand, the CIA notified the FBI, which put the Ames' under surveillance. The FBI planted bugs in Ames home, car and office. They also discovered that Ames had neglected to turn off an automated save feature in his word processor, thus leaving a trail of incriminating letters written to the Soviets. The FBI also obtained that Rosario was aware of her husband's activities and that she pressured him to continue his spying activities.
CIA officials quietly moved Ames into an area where he was not privy to classified information. He was planning however, to travel overseas for a conference and the FBI was worried that he might be tipped off and flee. He was summoned to work on February, 21, 1994 for a routine matter but was instead intercepted and arrested by FBI agents. Rosario was simultaneously arrested at the couple's home.
Aldrich Ames offered to cooperate with the U.S. Government if they would release Rosario and not charge her with any crimes. The government, however, had enough evidence on her to prosecute so they refused a deal. Rosario was nowhere near as loving towards her husband, blaming him for deceiving and manipulating her. She was convicted and sentenced to five years in prison and was promptly deported upon her parole. She moved back to Columbia where her mother was caring for the Ames' son.
Aldrich Ames was sentenced to life in a federal prison.