After meeting Gubitchev, Coplon and her Soviet handler were confronted by FBI agents. After trying to flee, both were apprehended and arrested. Coplon had numerous top-secret documents on her person, including the one provided by Hoover. Coplon was charged with treason and espionage and Gubitchev was charged with espionage.

Coplon faced two trials, one in Washington and one in New York. She was convicted in both. Gubitchev was convicted and deported. Coplon convictions were overturned, as an Appeals Court ruled that the FBI had illegally recorded conversations between Coplon and her attorney and further that the FBI had arrested her without an arrest warrant.

Married one of her attorneys and moved to New York where she settled down as a housewife.