As he planted a backpack containing a bomb just feet from a group of children, Dzhokhar Tsarnaev made a cold-hearted decision aimed at spreading terror and punishing America for its wars in Muslim countries, a federal prosecutor told jurors today during closing arguments in Tsarnaev's death penalty trial. "There was nothing about this day that was a twist of fate," says Assistant US Attorney Aloke Chakravarty. "This was a cold, calculated terrorist act. This was intentional. It was bloodthirsty. It was to make a point. It was to tell America that we will not be terrorized by you anymore. We will terrorize you." Bombs allegedly set by Tsarnaev and his brother killed an eight-year-old boy, two women, and wounded more than 260 people.
Prosecutors used their closing argument to remind the jury of the horror of that day, showing photographs and video of the carnage and chaos after the twin pressure-cooker bombs exploded. In a video that showed the aftermath of the first blast, jurors could hear the agonizing screams of Krystle Campbell, 29, who bled to death on the sidewalk. Taking aim at the argument that Tsarnaev was led astray by his older brother, Chakravarty repeatedly referred to the Tsarnaevs as "a team" and "partners" in the attack. Tamerlan Tsarnaev died four days after the bombings after he was shot by police and run over by Dzhokhar during a getaway attempt. If Dzhokhar is convicted—a near certainty, considering that his lawyer says he took part in the crime—the jury will begin hearing evidence on whether he should get life in prison or a death sentence. (Read more Boston Marathon bombing stories.)