Video: The Massachusetts Bay Transportation Authority SWAT team - the four men who took the Boston Marathon bombing suspect into custody - detail the arrest of Dzhokhar Tsarnaev.
From his hospital bed, Dzhokhar Tsarnaev has acknowledged his role in planting the explosives near the marathon finish line on April 15, the officials said. The first successful large-scale bombing in the post-Sept. 11, 2001, era, the Boston attack killed three people and wounded more than 250 others.
See the names and stories of the Boston Marathon victims
The officials, who spoke on condition of anonymity to describe an ongoing investigation, said Dzhokhar and his older brother, Tamerlan, who was killed by police as the two attempted to avoid capture, do not appear to have been directed by a foreign terrorist organization.
Rather, the officials said, the evidence so far suggests they were “self-radicalized” through Internet sites and U.S. actions in the Muslim world. Dzhokhar Tsarnaev has specifically cited the U.S. war in Iraq, which ended in December 2011 with the removal of the last American forces, and in Afghanistan, where President Obama has made plans to end combat operations by the end of 2014.
Obama has made repairing U.S. relations with the Islamic world a foreign policy priority, even as he has expanded drone operations in Pakistan and other countries that have inflamed Muslim public opinion.
Dzhokhar Tsarnaev has provided limited information to authorities that indicates he and his brother acted independently, without direction or significant influence from Islamist militants overseas. U.S. officials said they are still working to assemble a detailed timeline of a trip the older Tsarnaev took to Russia, but see no evidence that he received instructions there that led to the attack.
“These are persons operating inside the United States without a nexus” to an overseas group, a U.S. intelligence official said.
U.S. officials have said that the FBI questioned Tamerlan Tsarnaev at the behest of Russian authorities who had become concerned that he was becoming radicalized. The request was conveyed to officials at the U.S. Embassy in Moscow. U.S. officials said they sought follow-up information from Russia, but that Moscow failed to respond.
Officials also expressed skepticism that Russian authorities were concerned about the elder Tsarnaev’s contacts during his trip to Russia. “The evidence points to the fact that they let him into the country and let him out of the country,” the U.S. official said. “They didn’t take any legal action, which they could have while he was there.”
Dzhokhar Tsarnaev was charged Monday with using a weapon of mass destruction and malicious destruction of property, counts that could carry the death penalty if convicted. He made his first court appearance in an unusual, non-public proceeding in which a federal judge and several lawyers went to his hospital bed in Boston.
The criminal complaint against Tsarnaev, filed in U.S. District Court in Boston, ended a debate over how the case should be handled. Some congressional Republicans had insisted that Tsarnaev be designated an “enemy combatant,’’ which would enable the government to charge him under the laws of war in a military commission or to hold him indefinitely.