LaRose, who is scheduled to be sentenced today, and another woman were scooped up first by authorities. Khalid was secretly arrested when he was 17 and later indicted — based in part on grand jury testimony from LaRose, according to court documents.

FBI agents had previously visited Khalid at his home, but he continued with his online work, prosecutors wrote.

"Khalid simply obtained a new computer, hacked into a third party's Internet connection and started up his activity once again," they wrote. "When Khalid learned that he had been referenced as an unindicted co-conspirator in the [LaRose] indictment … he boasted about it to strengthen his bona fides among his online associates."

Lindy said Khalid did not have an attorney during those early meetings and his parents believed the agents were there to help their son.

Despite his stellar high school record, logs of online chats with another man convicted in a separate terror case indicated Khalid's dissatisfaction with life in Howard County. Khalid once told the man he had been daydreaming about "us both doing martyrdom operations together … in my school."

"The place where i live is a HOTBED of nsa and all the security agencies of amrika… and the kids who study in my school proudly state that their parents work in NSA and FBI," Khalid wrote, according to the logs cited in court documents. "it p****s me off."

Lindy described the chats as "classic juvenile adolescent puffing and boasting."

And a few minutes after discussing an attack on his school the other man asked Khalid whether he had ever fired a gun.

"I never touched one," Khalid wrote.

"Oh," the other man wrote. "It's not as easy as it looks."