"Now we know that was a mistake," a relative said. "We had thought everything was taken care of and fine because he talked to the FBI so many times - but the next thing you know, a year later, without any warning, the FBI took Mohammed away. It was a shock to us and to him."
Family members spoke on condition of anonymity. The Inquirer is not publishing the boy's last name because he is a juvenile and the specific charges have not been made public.
Federal charges against juveniles are rare. Nationally, only 100 juveniles are serving federal sentences, and federal officials could not cite another juvenile who has been arrested on terror-related charges.
Mohammed's arrest came six months after LaRose, who called herself "Jihad Jane" on websites, pleaded guilty to conspiracy to provide material support to terrorists, including providing a U.S. passport, and lying to FBI agents about it. A coconspirator, Jamie Paulin-Ramirez of Leadville, Colo., pleaded guilty to providing material aid to terrorists.
U.S. counterterrorism officials have said the Jihad Jane case represents a new and alarming threat - suburban, American-born women aiding Islamic terror groups.
Prosecutors said LaRose worked obsessively on her computer "to communicate with, recruit, and incite other jihadists." In 2009, she agreed to help try to kill the Swedish artist Lars Vilk, whose 2007 drawing of a dog with the head of the prophet Muhammad offended some Muslims.
Mohammed K.'s relatives said they do not know much about the allegations - or what Mohammed told the FBI - but are confused and angry that they allowed the boy to spend so much time with agents.
"When they said, 'Can we take him out for a few hours?' it seemed so informal," one relative said. "And now, in a way, we feel cheated."
