The most serious charge would be the use of a weapon of mass destruction to kill people, which carries a possible death sentence. Three people died in the twin explosions in Boston and more than 180 were injured.
Massachusetts does not have the death penalty, and it remains to be seen whether the administration would try to persuade a jury to sentence Tsarnaev to death. The state could try to bring charges against him, including for the death of Sean Collier, the Massachusetts Institute of Technology police officer who authorities say was killed by Tsarnaev and his brother, Tamerlan.
An early question that arose after Tsarnaev's capture on Friday was how to conduct his initial interrogation.
The administration said it would not immediately inform him of legal protections known as the Miranda rights. Instead, prosecutors planned to invoke a public safety exception created by the need to protect police and the public from immediate danger.
The American Civil Liberties Union's executive director, Anthony Romero, said the exception applies only when there's a continued threat to public safety, like whether there is imminent danger from other bombs, and is "not an open-ended exception" to the Miranda rule.
The federal public defender for Massachusetts, Miriam Conrad, said her office expects to represent Tsarnaev after he is charged and that he needs a lawyer appointed as soon as possible because there are "serious issues regarding possible interrogation."
But several congressional Republicans said Tsarnaev's rights should be even more restricted than the administration intends.
"I am disappointed that it appears this administration is once again relying on Miranda's public safety exception to gather intelligence which only allows at best a 48-hour waiting period that may expire since the suspect has been critically wounded," Sen. Saxby Chambliss of Georgia, the top Republican on the Senate Intelligence Committee, said in a statement hours after Tsarnaev was captured.