Boston Marathon Bomber Dzhokhar Tsarnaev Sentenced to Death

Boston Marathon bomber Dzhokhar Tsarnaev has been sentenced to death for helping to carry out the 2013 attack that killed three people and injured 264 at the world-renowned race, taking 15 hours to reach a decision.

The verdict's announcement came less than an hour after the U.S. Attorney for the District of Massachusetts tweeted that the jury had reached its decision.

The bombing killed three people and injured more than 260 others. Tsarnaev killed a Massachusetts Institute of Technology police officer days later.

Multiple victims of the attack, their families, as well as the family of the Tsarnaev brothers that conducted the bombing, all made their way to the courtroom to hear the sentencing announcement Friday afternoon.

"We know all too well that no verdict can heal the souls of those who lost loved ones, nor the minds and bodies of those who suffered life-changing injuries from this cowardly attack," Attorney General Loretta Lynch said in a statement following the verdict.

But prosecutors portrayed Tsarnaev as an equal partner in the attack and so heartless he placed a bomb behind children, killing an 8-year-old boy.