Ana Belén Montes is a former American senior analyst at the Defense Intelligence Agency who, from 1985 to 2001, handed over U.S. military secrets to Cuba. On September 21, 2001, she was arrested and subsequently charged with conspiracy to commit espionage for the government of Cuba.
(From: http://www.cnn.com/2016/07/06/us/declassified-ana-montes-american-spy-profile/index.html)