Jerry Chun Shing Lee, who worked for the CIA from 1994 to 2007, was arrested in 2018 for gathering classified information that he intended to pass on to the Chinese government. He was approached in 2010 by two Chinese intelligence officers who offered to pay him for classified information. He was indicted on one count of conspiracy to gather or deliver national defense information to a foreign government, and two counts of unlawfully retaining documents related to national defense. He was sentenced to 19 years in prison in November of 2019.
(From: https://www.businessinsider.com/jerry-chun-shing-lee-china-cia-secrets-2018-5)
Commentary on Lee's arrest