Boston Marathon Bomber Tsarnaev 'Wanted to Punish U.S.' — Prosecutor

Accused Boston Marathon bomber Dzhokhar Tsarnaev "wanted to punish America" when he killed three people and injured 264 with a pair of homemade bombs at the race on Apr. 25, 2013, a federal prosecutor said on Monday.

In closing arguments before a jury decides whether Tsarnaev, 21, is guilty of the bombing and of fatally shooting a police officer three days later, Assistant U.S. Attorney Aloke Chakravarty described the attacks as a deliberate, extremist act.

"The defendant thought that his values were more important than the people around him. He wanted to awake the mujahedeen, the holy warriors," Chakravarty said. "He wanted to terrorize this country. He wanted to punish America for what it was doing to his people."

Tsarnaev could be sentenced to death if the jury that heard 16 days of testimony against him finds him guilty of the attack.

His lawyers opened the trial a month ago with a blunt admission, that "it was him" who carried out the attack. But they contended that Tsarnaev did so not out of his own ideological anger but out of a sense of subservience to his older brother, 26-year-old Tamerlan, who prosecutors say was his partner in the attack.

Tamerlan died early on April 19, 2013, following a gunfight with police that ended when Dzhokhar sped off in a car, running his brother over in the process. Dzhokhar later found a hiding spot in a boat in a backyard, where he wrote a note suggesting the attack was an act of retribution for U.S. military campaigns in Muslim-dominated countries.

Tsarnaev's attorneys will deliver their closing argument later on Monday.

Monday's closing statements could be a preview of the arguments each side plans to make during the next phase of the trial, when the same jury will hear a fresh round of witness testimony before determining whether to sentence Tsarnaev to life in prison without possibility of parole, or to death.

Witnesses in the trial testified that Dzhokhar Tsarnaev's fingerprints were not found on bomb-making material at his brother's Cambridge, Massachusetts, apartment and that extremist literature found on his computer, including copies of al-Qaida's "Inspire" magazine, had initially been downloaded by Tamerlan.

The jury also saw images of Dzhokhar Tsarnaev standing with a backpack in the crowd at the marathon's finish line minutes before the blasts that killed restaurant manager Krystle Campbell, 29, Chinese exchange student Lingzi Lu, 23, and 8-year-old Martin Richard. Tsarnaev is also accused of the fatal shooting of Massachusetts of Institute of Technology police officer Sean Collier, 26.

Richard's parents, William and Denise; dancer Heather Abbott, who lost both legs in the blast, and former Boston Police Commissioner Ed Davis were among the people who packed the courtroom for closing arguments.

The jury has yet to hear from Tsarnaev. So far, it has heard from friends and family of those who were killed, from 17 people who lost limbs in the attack, and from emergency responders, including a police officer who described wrestling with Tamerlan in his final moments.

The defendant, who moved to the United States from Russia about a decade before the attack, has sat quietly in court through the proceedings and has generally avoided looking at witnesses.

But if he is found guilty, he may testify during the sentencing phase of his trial, legal experts said.