A second Chinese national working for Apple has been accused of stealing trade secrets related to Apple’s self-driving car initiative, otherwise known as Project Titan.

The FBI is reportedly charging Jizhong Chen, an electrical engineer, with attempting to steal trade secrets, according to a recently unsealed federal complain (spotted by NBC Bay Area). Apparently, Apple began investigating Chen when another employee spotted him taking pictures “in a sensitive work space.”

When Apple’s Global Product Security team searched the employee’s computer, they found “thousands” of sensitive Apple files, such as schematics, manuals, pictures, and diagrams.

They also found about a hundred photographs taken at an Apple facility. One of the images found on Chen’s computer, showing an Apple-designed wiring harness for a self-driving car, was provided to the FBI.

Apple also learned that Chen had recently applied for a job at a Chinese autonomous vehicle firm that directly competes with Apple’s Project Titan. Chen was arrested just one day before he was scheduled to fly to China.

This is the second time in six months that a Chinese citizen working for Apple has been caught in corporate espionage.

In July 2018, the FBI charged former Apple employee Xiaolang Zhang with stealing trade secrets. Zhang had also applied for a job at a Chinese self-driving car firm and was intercepted by the FBI as he was attempting to board a flight to Beijing.

The new charges also come at a tense time between the U.S. and China. U.S. government officials have long accused China of stealing intellectual property from U.S. tech firms to benefit Chinese companies.

There has also seemingly been an uptick in indictments and accusations against Chinese nationals for spying on U.S. and other firms or attempting theft of trade secrets.

Apple is widely rumored to be working on self-driving car technology, though it isn’t clear if the company is developing an actual Apple Car or just underlying “autonomous systems.” Either way, the so-called Project Titan has been described as one of Silicon Valley’s most poorly kept secrets.

Court documents reveal that Apple has about 5,000 employees with knowledge of Project Titan — including about 1,200 “core” employees who work directly on the project. Both Chen and Zhang were apparently part of this latter group.

Chen faces up to 10 years in prison a maximum fine of $250,000.