BOSTON -- The surviving suspect in the Boston Marathon bombings was charged Monday with "using a weapon of mass destruction" that resulted in three deaths, according to documents filed in federal court.
The suspect, Dzhokhar Tsarnaev, was charged by federal prosectors as he lay in a bed at Beth Israel Deaconess Medical Center, officials said.
In a criminal complaint unsealed Monday in United States District Court for the District of Massachusetts, Mr. Tsarnaev was charged with one count of "using and conspiring to use a weapon of mass destruction" against persons and property within the United States resulting in death, and one count of "malicious destruction of property by means of an explosive device resulting in death."
If he is convicted, the charges could carry the death penalty.
During the bedside arraignment, a magistrate judge advised Mr. Tsarnaev of his rights and the charges against him, according to court papers.
The affidavit accompanying the complaint provides the fullest picture to date of the evidence collected so far by F.B.I. agents and police detectives, who have been working around the clock since two blasts seconds apart silenced the cheering crowds and wrought chaos along the race's route.
The affidavit, sworn out by Daniel R. Genck, an F.B.I. special agent assigned to the Joint Terrorist Task Force in Boston, cites the surveillance video that helped identify the two suspects, and details their movements before the blasts, describing how and where they placed the backpacks that the complaint says contained bombs. It also describes Mr. Tsarnaev speaking on a cellphone, then apparently taking a photo with it.
It said that the explosive devices -- which it describes as "low-grade explosives that were housed in pressure cookers" that also contained "metallic BB's and nails" -- were placed near metal barriers along Boylston Street, where hundreds of spectators were watching the marathon runners as they approached the finish line.
In chilling detail, taken from surveillance video, the affidavit describes how a man it refers to as Bomber Two, which it identifies as Dzhokhar Tsarnaev, walks down Boylston Street toward the finish line with the thumb of his right hand hooked under the strap of his knapsack, and a cellphone in his left hand.
"He then can be seen apparently slipping his knapsack onto the ground," the affidavit said.
Video from the nearby Forum restaurant shows the bomber remaining in place, checking his cellphone, and even appearing to take a picture with it, the papers said. Then he appears to look at his phone, and appears to speak on it.
"A few seconds after he finishes the call, the large crowd of people around him can be seen reacting to the first explosion," the court papers said. "Virtually every head turns to the east (towards the finish line) and stares in that direction in apparent bewilderment and alarm. Bomber Two, virtually alone among the individuals in front of the restaurant, appears calm. He glances to the east and then calmly but rapidly begins moving to the west, away from the direction of the finish line."
"He walks away without his knapsack, having left it on the ground where he had been standing," the court papers said. "Approximately 10 seconds later, an explosion occurs in the location where Bomber Two had placed his knapsack."
In the court papers, Agent Genck says that he compared the driver's license photo of Mr. Tsarnaev to the video images, and that he believes "based on their close physical resemblance, there is probable cause that they are one and the same person." He also compared the driver's license photo of the other bombing suspect, Mr. Tsarnaev's brother, Tamerlan, with the video and said they were one and the same person.
The charges were announced one week after the 117th Boston Marathon began with a starter's gun and ended in two deadly bombings, shortly before a statewide moment of silence was planned for 2:50 p.m. to mark the moment that a pair of pressure-cooker bombs detonated.
Tamerlan Tsarnaev, 26, was killed after a shootout with the police in Watertown, Mass., early Friday, and his brother, Dzhokhar Tsarnaev, 19, was captured that night in Watertown and now lies grievously wounded in a Boston hospital bed. Law enforcement officials said the two men, of Chechen descent, also killed a campus police officer, carjacked a sport utility vehicle and critically wounded a transit police officer.
F.B.I. interrogators have been communicating with Mr. Tsarnaev, who is in the hospital with what investigators believe is a self-inflicted gunshot wound to the neck, according to a law enforcement official. Nothing that Mr. Tsarnaev has said -- it was unclear if he was able to speak, or had been communicating with the investigators in writing -- has led investigators to believe that there are other conspirators at large or unexploded devices that have not been recovered, the official said.
The government has also been pressing the Russian government for more details about a Russian request to the F.B.I. in 2011 about whether Tamerlan Tsarnaev had any links to extremist groups. The official described the Russians as "cooperative."
The White House said that Dzhokhar Tsarnaev would not be tried as an enemy combatant. "We will prosecute this terrorist through our civilian system of justice," said Jay Carney, the White House press secretary.
Mr. Carney noted that it was illegal to try an American citizen in a military commission, and that a number of high-profile terrorism cases were handled in the civilian court system, including that of the would-be bomber who tried to bring down a passenger jet around Christmas 2009 with explosives in his underwear.
Mr. Carney said the government had gotten "valuable intelligence" from suspects kept in the civilian judicial process. "The system has repeatedly proven it can handle" such cases, he said.
A memorial for Sean A. Collier, 26, the Massachusetts Institute of Technology patrol officer who law enforcement officials believe was shot dead in his patrol car Thursday night by the Tsarnaev brothers, was being planned for Wednesday, a university official said.
On Monday morning, hundreds of mourners attended a funeral at St. Joseph Church in Medford for Krystle Campbell, the 29-year-old restaurant manager killed near the finish line of the marathon, a race she tried to see every year.
The funeral was attended by her friends and relatives, as well as Gov. Deval Patrick and Representative Edward J. Markey. The mourners filed into the church as a single bell tolled. An overflow crowd lined the block.
Julie Dziamba, 21, who had worked at a restaurant called the Summer Shack where Ms. Campbell had been a manager, traveled from New London, N.H., to pay her respects. "She always had a smile on her face," Ms. Dziamba said, "even if she was mad at us for not cleaning up or getting things done on time."
The goodbyes to Ms. Campbell began Sunday. As Melanie Fitzemeyer, who baby-sat for Ms. Campbell two decades ago, walked to her wake Sunday along with hundreds of others, she took off her jacket and rolled up her sleeve. Incised on her arm was a two-line tattoo she had gotten the night before, at a parlor owned by one of Ms. Campbell's cousins.
"Boston Strong," the top line read in black letters scored into the length of her forearm, the surrounding skin still pink and tender.
"1983 Krystle 2013," read the bottom.
Ms. Fitzemeyer, 39, knew her longer than most, and remembered her as an exuberant child. "She liked to paint and color and make things," she said.
Some of the people wounded in the blasts remained in the hospital. A 7-year-old girl with multiple leg injuries was in critical condition at Boston Children's Hospital on Monday morning, along with an 11-year-old boy with a leg injury who was listed in fair condition, the hospital said in a statement. Eight other patients have been discharged, the hospital said.
Reassurance seemed to be the message from top city and state officials on the Sunday news shows.
Mayor Thomas M. Menino said that what he knew suggested that the two brothers suspected of carrying out the attack had operated by themselves. "All of the information that I have, they acted alone," he said on "This Week" on ABC.
The danger has passed, Governor Patrick said on "Face the Nation" on CBS. "The immediate threat, I think all of law enforcement feels, is over, based on the information we have," he said. "And that is a good thing, and you can feel the relief at home here."
Mayor Menino and Governor Patrick called on everyone in the state to come together for a moment of silence at 2:50 p.m. Monday -- precisely one week after the bombings. That will be followed by the ringing of bells across Boston and the commonwealth.
On Monday night at Boston University, students and faculty and staff members will gather on campus in honor of Lu Lingzi, 23, the Chinese graduate student who was killed in the bombing.
"We will remember her and everything good that a bright, ambitious, and engaging student represents in our community, and, hopefully, speak about the values that make our community strong, even under such terrible circumstances," Robert A. Brown, the president of the university, wrote in an e-mail announcing the gathering.
The fourth victim, Martin Richard, 8, was mourned on Sunday in Dorchester at the church attended by his family.
There were signs that the Boston area was returning to normal.
Late Sunday afternoon, Mayor Menino briefed reporters about a five-phase plan to reopen the area where the attack occurred. It will involve decontamination, structural building assessments and debris removal.
Newbury Street, the busy retail thoroughfare that runs parallel to Boylston Street, where the blasts took place, was bustling on Sunday, with visitors clutching shopping bags and relaxing in restaurants. But they were also drawn by the hundreds to gaze over the metal barriers cordoning off the six blocks around the marathon's finish line.
"It's been really eerie," said Calla Gillies, a 24-year-old real estate agent who lives inside the area, which she can gain access to with proof of residence. "We're just still as scared because it's empty. It feels like the marathon was yesterday."
Richard A. Oppel Jr. reported from Boston, and Michael Cooper and William K. Rashbaum from New York. Jess Bidgood contributed reporting from Boston, and Peter Baker from Washington.
This article originally appeared in The New York Times.