How a spy probe wound up as a child pornography prosecution

WASHINGTON (AP) — FBI agents investigating a potential data leak at Boeing obtained a secret warrant to search the home computers of a company manager in California for evidence they hoped would connect him to Chinese economic espionage.

At issue is how the government uses evidence derived through the Foreign Intelligence Surveillance Court and under what circumstances that information should be seen by defendants, particularly when it's repurposed for a routine criminal prosecution that has nothing to do with national security.

Judges can theoretically order prosecutors to share FISA information with defendants if they deem it necessary for challenging a search's legality, but courts have consistently agreed with the government that disclosing the material could expose sensitive intelligence secrets.

"For defendants, access to this information is a matter of fundamental fairness, because without it they cannot meaningfully challenge whether the government's secret searches were lawful in the first place," American Civil Liberties Union lawyer Patrick Toomey said in an email.

The FBI interviewed Gartenlaub multiple times in 2013 after a Wired.com article revealed a resemblance between a new Chinese aircraft, the Xian Y-20, and the Boeing C-17, a military cargo plane, and suggested someone within Boeing may have been responsible.

A separate FBI affidavit seeking access to Gartenlaub's Yahoo email account lays out the basis for suspicion, describing Gartenlaub as the "one engineer" who had access to C-17 data, intimate knowledge of Boeing's computer systems and family ties to China.