The U.S. Justice Department said it will seek the death penalty for Dzhokhar Tsarnaev, who is on trial for killing, maiming and injuring hundreds of people during the Boston Marathon in April 2013.
In a statement submitted to a Boston court on Thursday, prosecutors explained their decision by citing the "heinous, cruel and depraved manner" of the attack, which killed three people and injured more than 260 others at the marathon finish line.
They also wrote that Tsarnaev, an ethnic Chechen, had shown a "lack of remorse" and accused him of a "betrayal of the United States," which had granted him asylum and then citizenship.
"Dzhokhar Tsarnaev targeted the Boston Marathon, an iconic event that draws large crowds of men, women and children to its final stretch, making it especially susceptible to the act and effects of terrorism," prosecutors said in their statement, published by The Boston Globe.
A man whose legs were badly burned and struck by shrapnel in the bombing, Jarrod Clowery, said the verdict would have "no bearing" on his life, adding that the attackers "were tried and convicted by a power higher than us the moment they did what they did."
But an auto shop owner who knew the Tsarnaev family, Gilberto Tercetti Jr., said that although he was pleased with the prosecutors' decision, he might have preferred to see Tsarnaev sentenced to life without parole, because in some ways "death is too easy."
Massachusetts Governor Deval Patrick said that "one way or another, based on the evidence, Tsarnaev will die in prison."
In potential death penalty cases, federal prosecutors must declare at the outset whether they are seeking the death penalty. U.S. Attorney General Eric Holder authorized federal prosecutors to seek capital punishment for Tsarnaev upon conviction, saying, "The nature of the conduct at issue and the resultant harm compel this decision."
Tsarnaev, now 20, faces 30 charges in connection with the bombing that plunged the region into terror for five days before his arrest. Tsarnaev's brother, Tamerlan, who allegedly joined him in the attack, was killed in a confrontation with police.
The Tsarnaev family moved from Dagestan, a Russian republic that has been battling against Islamic insurgency in recent years, to the U.S. about a decade ago, and Dzhokhar Tsarnaev was sworn in as a naturalized U.S. citizen in September 2012.