Among the documents were forms for nine of 10 young men from the eastern French city of Strasbourg, all recruited by a man named Mourad Fares. One of them, Karim Mohammad-Aggad, described barhopping in Germany with Fares. He told investigators that ISIS recruiters used "smooth talk" to persuade him.

He'd traveled with his younger brother and friends to Syria in late 2013. Two died in Syria, and within a few months, seven returned to France and were arrested. Mohammad-Aggad's brother, 23-year-old Foued, returned to Paris and was one of the three men who stormed the Bataclan in a night of attacks Nov. 13 that killed 130 people.

"My religious beliefs had nothing to do with my departure," Karim Mohammad-Aggad told the court, before being sentenced to nine years in prison. "Islam was used to trap me like a wolf," he said.