UPDATE 3:39 P.M. EDT: Tsarnaev's arraignment has been scheduled for July 10.
UPDATE 3:25 P.M. EDT: Ortiz elaborated on the motive the Tsarnaevs allegedly had for carrying out the bombing.
"They took these acts as an explanation, in some ways, to effect what United States foreign policy may be, and also as a measure of perhaps a protest agaisnt what they viewed or perceived as actions by the United States in foreign countries," she said.
UPDATE 3:09 P.M. EDT: Massachusetts U.S. Attorney Carmen Ortiz outlined the indictment handed down against Tsarnaev during a news conference Thursday afternoon.
"The defendant's alleged conduct forever changed lives," she said. The charges against Tsarnaev include conspiracy to use and using a weapon of mass destruction, conpsiracy to bomb and bombing a place of public use, carjacking and weapons charges.
Ortiz said the indictment detailed how Tsarnaev and his brother, Tamerlan Tsarnaev, took pre-meditated steps in the days before the bombing.
The Tsarnaev brothers allegedly traveled to a gun range in Manchester, N.H., on March 20, where Dzhokhar purchased 200 rounds of ammunition.
Ortiz alleged that Tamerlan Tsarnaev ordered electronic equipment that could be used to make the improvised explosive devices used in the Boston bombing.
The day before the April 15 bombing, Dzhokhar Tsarnaev allegedly bought a pre-paid cell phone account under the name "Jahar Tsarni," Ortiz said. Dzhokhar allegedly used the phone to speak to his brother during the Boston Marathon. Seconds after their conversation, Tamerlan Tsarnaev detonated the IED that killed Krystle Marie Campbell.
Moments after the first explosion, Dzhokhar detonated the bomb that killed spectators Linghzi Lu and Martin Richard, Ortiz alleged.
Ortiz said Dzhokhar "faces life, and possibly death, if convicted."
UPDATE 2:19 P.M. EDT: The full text of the indictment is embedded below.
A federal grand jury has indicted Boston Marathon bombing suspect Dzhokhar Tsarnaev on terrorism charges, the U.S. Attorney’s Office in Boston announced Thursday afternoon.
Tsarnaev, 19, was charged with using weapons of mass destruction and killing four people: three Boston Marathon spectators and an MIT policeman.
A press conference on the indictment handed down against Tsarnaev is scheduled for 3 p.m. EDT in Boston, the U.S. attorney’s office tweeted.
Press conference on Tsarnaev indictment at 3:00 p.m. U.S. District Court in Boston, 9th floor
— U.S. Attorney MA (@DMAnews1) June 27, 2013
News of the indictment came as more details were revealed of the alleged confession written by Tsarnaev. Wounded and hiding in a boat in the backyard of a home in Watertown, Mass., Tsarnaev allegedly wrote that he and his brother, Tamerlan Tsarnaev, carried out the bombings in response to Muslims who were being killed around the world.
"We Muslims are one body, you hurt one you hurt us all," Tsarnaev wrote, according to the Boston Globe Twitter account, which cited federal authorities.
"Now I don't like killing innocent people... it is forbidden in Islam but due to said (unintellible) it is allowed," Tsarnaev went on to write.
Tamerlan Tsarnaev, 26, was killed in a shootout with authorities in Watertown three days after the bombings. Dzhokhar Tsarnaev escaped the firefight with injuries before being captured while hiding out in the boat.
Dzhokhar Tsarnaev has maintained his innocence, and told his mother in his first telephone call with her since the attacks that he's doing fine.
Read the indictment below: