Both charges carry a potential death sentence.
The action came almost exactly a week after two homemade bombs ripped through the crowd near the finish line of the 2013 Boston Marathon, killing three and injuring more than 200.
Mr. Tsarnaev was informed of the charges during an initial court appearance conducted by a federal judge in his hospital room.
The charges resulted from the work of a team of investigators from the Federal Bureau of Investigation, the Boston Police Department, the Massachusetts State Police, and a range of other federal investigative agencies.
According to a sworn affidavit filed with the charges, investigators used video and still photographs taken near the finish line of the marathon to identify two suspected bombers. The 10-page affidavit provides the most detailed statement to date of how law enforcement officials were able to identify and arrest the suspects.
“At approximately 2:38 p.m. (based on the video's duration and timing of the explosions) – i.e., approximately 11 minutes before the first explosion – two young men can be seen turning left (eastward) onto Boylston from Gloucester Street. Both men are carrying large knapsacks,” the affidavit says.
The affidavit identifies the men from the color of their hats. Bomber One is wearing a black baseball style hat, and Bomber Two is in a white hat. Federal officials have identified Bomber One as Tamerlan Tsarnaev and Bomber Two as his younger brother, Dzhokhar.
“After turning onto Boylston Street, Bomber One and Bomber Two can be seen walking eastward along the north side of the sidewalk towards the Marathon finish line. Bomber One is in front and Bomber Two is a few feet behind him.” The affidavit continues: “At approximately 2:42 p.m. (i.e., approximately seven minutes before the first explosion), Bomber One can be seen detaching himself from the crowd and walking east on Boylston Street towards the Marathon finish line.”
“Approximately 15 seconds later, he can be seen passing directly in front of the Forum Restaurant and continuing in the direction of the location where the first explosion occurred,” the affidavit says. “His knapsack is still on his back.”
The affidavit continues: “At approximately 2:45 p.m., Bomber Two can be seen detaching himself from the crowd and walking east on Boylston Street toward the Marathon finishing line. He appears to have the thumb of his right hand hooked under the strap of his knapsack and a cell phone in his left hand. Approximately 15 seconds later, he can be seen stopping directly in front of the Forum Restaurant and standing near the metal barrier among numerous spectators, with his back to the camera, facing the runners.”
The FBI agent who filed the affidavit, Daniel Genck, then uses an unusual word in his description of the unfolding drama. That word is “apparently.”
The affidavit continues: “He [Bomber Two] then can be seen apparently slipping his knapsack onto the ground. A photograph taken from the opposite side of the street shows the knapsack on the ground at Bomber Two's feet.”
The agent notes that video from the Forum Restaurant shows that Bomber Two stood in the same spot for approximately four minutes. He occasionally looked at his cell phone.
“Approximately 30 seconds before the first explosion, he lifts his phone to his ear as if he is speaking on his cell phone, and keeps it there for approximately18 seconds. A few seconds after he finishes the call, the large crowd of people around him can be seen reacting to the first explosion. Virtually every head turns to the east (towards the finish line) and stares in that direction in apparent bewilderment and alarm.”
Genck’s affidavit notes that Bomber Two was the only person in front of the restaurant who 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. Approximately 10 seconds later, an explosion occurs in the location where Bomber Two had placed his knapsack.”
In addition to the bombing, the affidavit also details key portions of events on Thursday and Friday when the two men appeared to be in the midst of a desperate but unsuccessful attempt to flee Boston.
The formal charge against Tsarnaev is using a weapon of mass destruction. Although those are the words in the applicable statute, the law covers improvised explosive devices (IEDs) such as those allegedly used at the Boston Marathon. It does not mean that Tsarnaev and his brother were attempting to destroy the entire city.
The charges were filed as officials acknowledged that Tsarnaev was responding to inquiries from federal agents although he cannot talk and is still listed in serious condition in a Boston hospital.
The suspect is described as unable to verbally communicate after sustaining injuries to his throat and elsewhere during the massive manhunt on Thursday and Friday. But a special interrogation team is said to have started efforts to elicit key information about the bombing and the two brothers at the center of the alleged plot.
Officials are relying on a public safety exception to the usual rule that criminal suspects be advised of their right to consult a lawyer and their right to remain silent during police questioning.
The so-called Miranda warnings are intended to ensure that any statements made by a suspect are made knowingly and without coercion and, thus, may be admitted as evidence against the suspect in an eventual court case.
But that is not the only reason US officials want and need information from Tsarnaev. Federal officials are seeking critical intelligence information from him. They want to know if there are accomplices who might seek to carry out additional bombings. They also want to know if the Tsarnaev brothers were working in concert with any organized group in the US or overseas.
The public safety exemption as advocated by the Obama administration would allow such intelligence gathering without a Miranda warning, and might even allow the information to be used as evidence in an eventual trial.
Tsarnaev’s case could become a test case for that proposition.
Nonetheless, many legal analysts say federal agents and prosecutors may already possess more than enough evidence from other sources to convict Tsarnaev at trial without having to rely on how he might nod or shake his head or move his eyes while lying sedated in a hospital bed.
The initial contacts with the suspect took place as the Obama administration effectively ended what had been an ongoing debate over how best to handle and interrogate Tsarnaev.
White House spokeman Jay Carney said earlier on Monday that the administration had concluded that the suspect would not be treated as an enemy combatant. He said it would violate US law to place a US citizen on trial before a military commission rather than in federal court.
Mr. Carney said the nation’s civilian federal court system had repeatedly proved to be effective in trying and convicting suspected terrorists.
Republican Sens. John McCain and Lindsey Graham had urged that Tsarnaev be classified as an enemy combatant and shifted to military custody to facilitate open-ended interrogation without interference from defense lawyers or the courts.
Democratic Sen. Carl Levin and others said there is no legal basis to detain Tsarnaev as an enemy combatant because there is no evidence – at this stage – that he was part of Al Qaeda, the Taliban, or an associated group.
Under US law, individuals suspected of a crime who are taken into police custody are either charged or released. The defendant’s case is presented to a neutral judge, who ensures that the defendant’s rights are being respected.
That is true in all criminal cases, from the lowly tax cheat to the most sophisticated mass-murdering terrorist. The US Constitution and its protections do not come with an on-off switch.
But there is one important exception. After the 9/11 attacks, Congress passed the Authorization to Use Military Force (AUMF). The law empowered the US military to take action against Al Qaeda, the Taliban, and any associated forces. That provision has been interpreted to authorize the military detention of terrorism suspects.
It is under that authority that the 166 detainees at Guantánamo are being held in a US military prison camp.
Less clear is whether the AUMF authorizes open-ended military detention without charge of a US citizen arrested on US soil for suspected involvement in a bombing in the US.
Tsarnaev is believed to be a naturalized US citizen. Federal agents are expected to ask him – prior to advising him of his right to remain silent – whether he or his older brother have any connection to Al Qaeda or Islamic militants in Chechnya who in the past have maintained an association with Al Qaeda.
Without such a connection, Congress’s Authorization to Use Military Force would not appear to apply to an individual who acted outside of any such group.