U.S. authorities continue to seek information from the surviving suspect in last week's deadly Boston Marathon bombings who is facing charges of using a weapon of mass destruction.
The suspect, Dzhokhar Tsarnaev, 19, was formally charged Monday in his hospital room, where he is recovering from several gunshot wounds. He could face the death penalty if convicted for the blasts that killed three people and injured more than 170 others. His initial appearance in court was set for May 30.
As the investigation into the bombings continues, U.S. media reports say Tsarnaev has conveyed to authorities in writing that he and his older brother, Tamerlan, 26, acted alone, without any support from overseas groups. Those reports cannot be independently confirmed. Officials have not publicly revealed a motive for the attack.
Tamerlan Tsarnaev died in a shootout with police late Thursday, a day before his younger brother was captured.
Attorney General Eric Holder said the charges against Dzhokhar Tsarnaev show "Those who target innocent Americans and attempt to terrorize our cities will not escape from justice."
"We will hold those who are responsible for these heinous acts accountable to the fullest extent of the law," he added.
The 19-year old suspect is also charged with malicious destruction of property
Boston returned to some sense of normalcy Monday. Commuters filled highways, children walked to schools and businesses opened their doors.
But the northeastern U.S. city paused at 2:50 p.m. (local time EDT) for a moment of silence to mark the passing of a week since the deadly explosions.
The two suspects are ethnic Chechen immigrants who came to the United States as boys. Authorities say they do not believe the brothers were affiliated with a larger terrorist network and that they had acted alone.