An ex-CIA officer has been sentenced to 20 years in prison after he was convicted of trying to sell U.S. defense documents to Chinese intelligence agents.

Kevin Mallory, age 62, from Leesburg, Virginia, had worked for the CIA for many years in China and is fluent in Chinese. He held high-level U.S. government security clearances for assignments he performed on behalf of various agencies in China, Taiwan, Iraq, and Washington.

Mallory had offered to sell classified defense information to Chinese intelligence during trips he made to Shanghai in March and April 2017, for which he was paid $25,000. He was sentenced in federal court May 17 for violating the Espionage Act.

Mallory’s attorneys have said they plan to appeal the conviction.

Mallory is one of several U.S. intelligence officers who have been convicted of espionage on behalf of China just in the past year. Earlier this month, another former CIA officer, Jerry Chun Shing Lee, also pleaded guilty to federal charges of spying for China. Lee faces a possible life sentence after exposing a network of CIA informants.

In March of this year, Ron Rockwell Hansen, a former officer for the Defense Intelligence Agency (DIA), also pleaded guilty to espionage-related charges after he received hundreds of thousands of dollars from Beijing.

Assistant Attorney General John Demers issued a statement shortly after Mallory’s sentencing. “This case is one in an alarming trend of former U.S. intelligence officers being targeted by China and betraying their country and colleagues,” Demers said. “This sentence, together with the recent guilty pleas of Ron Hansen and Jerry Lee, deliver the stern message that our former intelligence officers have no business partnering with the Chinese or any other adversarial foreign intelligence service.”