The jury which sentenced Dzhokhar Tsarnaev to death for the Boston Marathon bombing swept aside pleas that he was just a "kid" who fell under the influence of his fanatical older brother.
The decision in America's most closely-watched terrorism trial in decades - which came just over two years after the April 15, 2013, bombing that killed three people and wounded more than 260 - brought relief and grim satisfaction to many in Boston.
"We can breathe again," said Karen Brassard, who suffered shrapnel wounds to her legs.
The death sentence sets the stage for what could be America's first execution of a terrorist in the post-September 11 era, though the case is likely to go through years of appeals.
In the meantime, Tsarnaev will probably be sent to death row at the federal prison in Terre Haute, Indiana, where Oklahoma bomber Timothy McVeigh was put to death in 2001.
A sombre-looking Tsarnaev stood with his hands folded, his head slightly bowed, as he learned his fate, sealed after 14 hours of deliberations over three days. His lawyers left court without comment.
His father, Anzor Tsarnaev, reached by phone in the Russian region of Dagestan, let out a deep moan upon hearing the news and hung up.
The Tsarnaevs - ethnic Chechens - lived in the former Soviet republic of Kyrgyzstan and the volatile Dagestan region, near Chechnya, before moving to the US about a decade before the bombings. They settled in Cambridge, just outside Boston.
The 12-member federal jury had to be unanimous for Tsarnaev to get the death penalty. Otherwise, the former college student would have automatically received life in prison with no chance of parole.
In weighing the arguments for and against death, the jurors decided among other things that Tsarnaev showed a lack of remorse. And they emphatically rejected the defence's central argument - that he was led down the path to terrorism by his big brother.
The attack and the ensuing manhunt paralysed the city for days and cast a pall over the marathon - normally one of Boston's proudest, most exciting moments - that has yet to be lifted.
Tsarnaev was convicted last month of all 30 charges against him, including use of a weapon of mass destruction, for joining his now-dead brother, Tamerlan, in setting off two shrapnel-packed pressure-cooker bombs near the finish line of the race. Tsarnaev was also found guilty in the killing of an MIT police officer during the getaway.
Seventeen of the charges carried the possibility of a death sentence; ultimately, the jury gave him the death penalty on six of those counts.
Tsarnaev's chief lawyer, death penalty specialist Judy Clarke, admitted at the very start of the trial that he participated in the bombings.
But Clarke argued that Dzhokhar was an impressionable 19-year-old led astray by his domineering 26-year-old brother, Tamerlan. The defence portrayed Tamerlan as the mastermind of the plot to punish the US for its wars in Muslim countries.
Tamerlan died days after the bombing when he was shot by police and run over by Dzhokhar during a chaotic getaway attempt.
Prosecutors depicted Dzhokhar as an equal partner in the attack, saying he was so cold-hearted he planted a bomb on the pavement behind a group of children, killing an eight-year-old boy.
To drive home their point, prosecutors cited the message he scrawled in the dry-docked boat where he was captured: "Stop killing our innocent people and we will stop."
And they opened their case in the penalty phase with a startling photo of him giving the finger to a security camera in his jail cell months after his arrest.
"This is Dzhokhar Tsarnaev -unconcerned, unrepentant and unchanged," prosecutor Nadine Pellegrini said.
The jurors also heard grisly and heartbreaking testimony from numerous bombing survivors who described seeing their legs blown off or watching someone next to them die.
Killed in the bombing were Lingzi Lu, a 23-year-old Boston University graduate student from China; Krystle Campbell, a 29-year-old restaurant manager; and eight-year-old Martin Richard, who had gone to watch the marathon with his family. Police Officer Sean Collier was gunned down in his cruiser days later. Seventeen people lost legs in the bombings.
The speed with which the jury reached a decision surprised some, given that the jurors had to fill out a detailed worksheet in which they tallied up the factors for and against the death penalty.