(CNN) — The surviving suspect in the Boston Marathon bombings has indicated that his older brother, not any international terrorist group, masterminded the deadly attack, a U.S. government source said.
Dzhokhar Tsarnaev, who has been hospitalized with a tube down his throat since Friday, communicated with investigators by writing and nodding.
The preliminary interviews with Tsarnaev suggest the two brothers fit the classification of self-radicalized jihadists, the government source said.
Tsarnaev has conveyed to investigators that Tamerlan’s motivation stemmed from jihadist thought and the idea that Islam is under attack, and jihadists need to fight back, the source said Monday.
The government source cautioned that the interviews were preliminary, and that Tsarnaev’s account needs to be checked out and followed up on by investigators.
A federal law enforcement official told CNN that while investigators have seen no indication the suspects collaborated with others, they still have plenty of work to do before they can confidently say no one else was involved in the April 15 attack that killed three people and wounded more than 260 others. That official would not comment on any motive or specifics on what Dzhokhar Tsarnaev has communicated to officials.