A former substitute teacher from Texas has been indicted for allegedly trying to work as an English teacher for ISIS.

Warren Christopher Clark, 34, was captured recently by the Syrian Democratic Forces, the Justice Department said.

Clark had allegedly submitted a resume and cover letter to the Islamic State, noting that he had a bachelor’s degree from the University of Houston, worked as a substitute teacher in Sugar Land, Texas, and had done teaching stints in Saudi Arabia and Turkey.

“Dear Director, I am looking to get a position teaching English to students in the Islamic State,” he wrote in the cover letter. “Teaching has given me the opportunity to work with people from diverse cultural backgrounds and learning capabilities.”

An indictment unsealed on Friday charges Clark with attempting to provide himself as material support to ISIS.

“The FBI continues to aggressively pursue individuals who attempt to join the ranks of ISIS’s foreign fighters or try to provide support for other terrorist organizations. This fight against terrorism is not one we can combat alone,” said Perrye Turner, the special agent in charge of the FBI’s office in Houston.

If convicted, Clark could face up to 20 years in prison.