WASHINGTON - The surviving Boston Marathon bombing suspect told FBI agents from his hospital bed that he and his brother were driven to the attack by jihadist radicalism sparked by the U.S. wars in Iraq and Afghanistan in which thousands of Muslims have died, a federal law enforcement official familiar with the inquiry said Tuesday.
Dzhokhar Tsarnaev, 19, who lay in a Boston hospital with multiple gunshot wounds, also said that he and his older brother, Tamerlan, learned how to make the pressure-cooker bombs used in the attack from an al-Qaida website, said the official, who spoke on condition of anonymity because details of the investigation are sensitive.
Tamerlan Tsarnaev, 26, died in a police shootout early Friday in which he hurled makeshift explosives at law enforcement officers before he was gunned down. He is believed to have instigated the attack that killed three people and injured more than 260 others after turning devoutly religious and possibly reading radical Islamic dogma on Internet sites or associating with radicals during visits to Russia, law enforcement officials said.
Relatives have suggested in news interviews that he would have held considerable sway over his younger brother, a college student.
No evidence has surfaced so far that the two Chechen brothers were influenced by a foreign terrorist organization to carry out the worst terrorist attack on U.S. soil since the suicide hijackings that toppled the World Trade Center, hit the Pentagon and crashed in a Pennsylvania field on Sept. 11, 2001.
But FBI agents have not foreclosed that possibility and will be conducting a worldwide investigation to examine the origins of their apparent radicalization, the law enforcement official said.
The FBI expects to conduct a lengthy investigation to determine for certain whether they acted alone, were assisted by other conspirators or received any assistance along the way, the official said.
The investigation also will examine whether they were involved in an unsolved triple murder, apparently carried out on the 10th anniversary of the Sept. 11 terror attacks, in Waltham, Mass., the law enforcement official said.
A friend of Tamerlan Tsarnaev's, 25-year-old Brendan Mess, was among three young men whose throats were slit, according to The Boston Globe.