SANTA ANA, Calif. (AP) -- An elderly Chinese-born engineer convicted of economic espionage for hoarding sensitive documents that included space shuttle details faces sentencing Monday, and prosecutors are seeking a 20-year term.
A judge found Dongfan "Greg" Chung, 74, guilty in July of six federal counts of economic espionage and other charges for keeping 300,000 pages of sensitive papers in his home. The documents also included information about the fueling system for a booster rocket.
Despite Chung's age, prosecutors have requested a 20-year sentence, in part to send a message to other would-be spies.
Assistant U.S. Attorney Greg Staples noted in sentencing papers that Chung amassed a personal wealth of more than $3 million while betraying his adopted country.
"The (People's Republic of China) is bent on stealing sensitive information from the United States and shows no sign of relenting," Staples wrote. "Only strong sentences offer any hope of dissuading others from helping the PRC get that technology."
Chung's attorney, Thomas Bienert Jr., did not return a call for comment. He has said his client will appeal.
Defense attorneys also filed a motion last week accusing prosecutors of withholding a report about an FBI interview with a Chinese professor with whom Chung corresponded.
The attorneys requested an evidentiary hearing for Monday on the matter.
It was unclear if U.S. District Judge Cormac J. Carney would grant the motion.
The government accused Chung, a stress analyst with high-level clearance, of using his 30-year career at Boeing Co. and Rockwell International to steal the documents. They said investigators found papers stacked throughout Chung's house that included sensitive information about the booster rocket -- documents that employees were ordered to lock away at the end of each day. They said Boeing invested $50 million in the technology over a five-year period.
During the non-jury trial, Chung's lawyers argued that he may have violated Boeing policy by bringing the papers home, but he didn't break any laws by doing so, and the U.S. government couldn't prove he had given secret information to China.
In his ruling, Carney wrote that the notion that Chung was merely a pack rat was "ludicrous" and said the evidence showed that he had been passing information to Chinese officials as a spy.
The government believes Chung began spying for the Chinese in the late 1970s, a few years after he became a naturalized U.S. citizen and was hired by Rockwell International.
Chung worked for Rockwell until it was bought by Boeing in 1996. He stayed with the company until he was laid off in 2002 but brought back a year later as a consultant. He was fired when the FBI began its investigation in 2006.
When agents searched Chung's house that year, they discovered more than 225,000 pages of documents on Boeing-developed aerospace and defense technologies, according to trial briefs.
The technologies dealt with a phased-array antenna being developed for radar and communications on the U.S. space shuttle and a $16 million fueling mechanism for the Delta IV booster rocket, used to launch manned space vehicles.
Agents also found documents on the C-17 Globemaster troop transport used by the U.S. Air Force as well as militaries in Britain, Australia and Canada -- but the government later dropped charges related to those finds.
Prosecutors discovered Chung's activities while investigating another suspected Chinese spy living and working in Southern California.
That man, Chi Mak, was convicted in 2007 of conspiracy to export U.S. defense technology to China and sentenced to 24 years in prison.