The jury in the Boston Marathon bombing trial has sentenced Dzhokhar Tsarnaev (21), an ethnic Chechen and naturalised American citizen, to death after deliberating for 14 hours.
The jury of seven women and five men convicted Mr Tsarnaev last month of all 30 charges against him, including 17 carrying the death penalty, over the twin blasts at the finish line of the Boston Marathon in April 2013 that killed three, including an eight-year-old boy, and injured more than 260 people, 17 of whom lost limbs.
The same jury sentenced him to death by the required unanimous decision of all 12 of its members.
The bombings were the worst attack on American soil since September 11th, 2001, and Mr Tsarnaev is the first terrorist to be sentenced to death by a jury in a case taken by the US government in the federal courts in the period since the 9/11 attacks.
He was also found guilty of the killing of a Massachusetts Institute of Technology police officer four days after the blasts, hours before his older brother and fellow bomber Tamerlan Tsarnaev, was killed during a confrontation with police sparking a city-wide manhunt.
The trial largely came down to whether Tsarnaev should face life or death after his lawyers admitted his involvement in the bombings making the initial guilt phase academic in many respects.
The prosecution painted Tsarnaev, who emigrated from Russia to Massachusetts with his family in 2002, as a cold-blooded killer making a political statement by murdering innocent Americans in vengence for the killing of Muslims in the US wars in Iraq and Afghanistan.
Tsarnaev’s defence lawyers argued that he had been acting under the influence of his self-radicalised, jihadist older brother.
Only three jurors believed that Tsarnaev had been swayed by Tamerlan in carrying out the devastating bombings.
Tsarnaev showed no reaction when the verdict was read, maintaining the emotionless stare he has kept for the majority of this long trial.
The prosecution and defence concluded their closing arguments on Wednesday in a trial that began with jury selection in January.
Prosecutors presented graphic and at times harrowing evidence during the trial showing video footage previously not seen publicly of a home-made pressure-cooker bomb exploding in Tsarnaev’s backpack.
The bomb was shown detonating behind a row of cheering children in a crowd next to a packed restaurant on Boylston Street in Boston.
Many witnesses testified about the aftermath of the twin bombings resembling a war zone after the bodies of dozens of people were shredded by flying shrapnel, ball bearings and pieces of burning metal.
Sydney Corcoran, who was badly injured in the bombings and whose mother lost both legs in the blasts, said on social media website Twitter: “My mother and I think that now he will go away and we will be able to move on. Justice. In his own words, ‘an eye for an eye.’”
US attorney general Loretta Lynch said in a statement that the death sentence was “a fitting punishment for this horrific crime.”
Steven Hawkins, executive director of Amnesty International USA, condemned the bombings but said the death penalty was “not justice” and would “only compound the violence.”
“It is outrageous that the federal government imposes this cruel and inhuman punishment, particularly when the people of Massachusetts have abolished it in their state,” he said.
The death sentence runs counter to public opinion in Massachusetts, which prohibits the death penalty in state cases. Polls showed that most people in the Boston area preferred a sentence of life without the possibility of parole rather than death.
The jurors were selected from a panel of people from the east Massachusetts area who had agreed to consider capital punishment in the case.
Among those sitting the court’s public gallery for the sentencing were Bill and Denise Richard, the parents of the youngest victim of the bombings Martin Richard (8).
The couple, in a newspaper article last month, called on the government to withdraw the death penalty to avoid years of appeals and further pain for the family as they endure further court hearings.
Appeals in death penalty cases are common and can last years, if not decades.
Of 80 people sentenced to death by juries in federal cases, only three, including the Oklahoma City bomber Timothy McVeigh have been executed, according to statistics cited by the New York Times.