Kurt Lessenthien, a Navy petty officer, was arrested April 1996 for attempted espionage after offering nuclear sub information to the Russians. He arranged to pass along classified information in exchange for thousands of dollars. In October 1996, Lessenthien was sentenced to life in prison.
(From: https://www.dhra.mil/PERSEREC/Espionage-Cases/1996/)
Historical Dictionary of Naval Intelligence by