The man who was carjacked and held hostage -- allegedly by the Tsarnaev brothers -- just outside Boston last week said he thought he heard the two men say "Manhattan" in their conversation, the commissioner said. The one-time hostage has told investigators the suspects spoke in another language, which may have been Chechen or Russian, while he drove with them.
Dzhokhar Tsarnaev was in New York in late 2012, likely in November, Kelly said.
The brothers used a remote control device similar those used to control toy cars to detonate the two bombs in Boston, Rep. Dutch Ruppersberger, a Maryland Democrat and member of the House Select Committee on Intelligence, said Wednesday.
The surviving suspect, Dzhokhar, has indicated that his older brother Tamerlan masterminded the attack and described he and his brother as self-radicalized jihadists, according to a U.S. government source.
The teenager cited the U.S. wars in Afghanistan and Iraq as motivating factors behind the attack, a U.S. government official said.
Dzhokhar told authorities that neither he nor his brother had had any contact with terrorist groups overseas, the U.S. government official said. But the official cautioned that the interviews were preliminary and that Tsarnaev's account needs to be checked out.
Dzhokhar Tsarnaev has been charged with using and conspiring to use a weapon of mass destruction resulting in death and one count of malicious destruction of property by means of an explosive device resulting in death.
The suspects' uncle said a friend of Tamerlan's "brainwashed" him. And the suspects' former brother-in-law said Tamerlan seemed to be influenced in Islam by a friend named Misha, but that he did not see Misha try to radicalize him.
Investigators had no immediate comment on reports of someone named "Misha."
Investigators are looking into the possibility Tamerlan Tsarnaev -- who was married with a young daughter, whom he frequently cared for while his wife worked as a home health aide -- may have helped finance the bomb plot through drug sales, according to a source familiar with the investigation.
Boylston Street reopens as slain officer is mourned
For more than a week, a stretch of Bolyston Street -- traditionally one of the busiest parts of Boston -- has been a crime scene in the aftermath of the blasts that left three dead.
Traffic has been barred from the thoroughfare and businesses have been closed.
On Wednesday, workers replaced missing bricks and patched up concrete on the street just before opening it to pedestrian traffic. Crews were repairing damage caused by the two bombs, which were placed near the marathon's finish line.
"I think that Boston is a tough city and it will be rejuvenated and ready to go," said David Sapers, owner of Sugar Heaven on Boylston Street.
Those wounded in the explosions, meanwhile, continued to recover as well.
Of the more than 260 people who were hurt, 33 remain hospitalized Wednesday night, according to a CNN tally. One person is in critical condition at Boston Medical Center.
In Cambridge, mourners gathered at the Massachusetts Institute of Technology campus to honor Campus Officer Sean Collier, the fourth person killed last week. Authorities believe the Tsarnaev brothers shot Collier as he sat in his patrol car Thursday night.