After many weeks of testimony, jurors begin debates in the trial of Dzhokhar Tsarnaev, he faces life in prison or the death penalty for working with his brother to explode bombs at the 2013 Boston Marathon.

The defense and prosecution made closing arguments in the case on Monday, April 6, 2015.

“He chose a day when there would be civilians on the sidewalks and he targeted those civilians: men, women and children. He wanted to terrorize this country. He wanted to punish America for what it was doing to his people,” said prosecutor Aloke Chakravarty.

The prosecutor showed a picture of Dzhokhar Tsarnaev and his brother Tamerlan in the marathon crowd.

Tsarnaev, 21 years old, is being accused of 30 different counts, including setting off weapons of mass destruction at a public event as an act of terrorism. Seventeen of those counts carry a sentence of death or life imprisonment.

If Tsarnaev is found guilty of one of the 17 capital counts, the trial will proceed to a second phase, the “penalty phase”.

This part of the trial has evidence of “aggravating and mitigating factors”, and the jury will be asked to weigh things that make this crime particularly terrible against details from Tsarnaev’s background and mental health history.

Since testimony started on March 4, federal prosecutors have called 92 witnesses, and the defense has called only four. “He was there,” defense attorney Judy Clarke said when the trial opened, but the defense has been focused on getting the jury to spare Tsarnaev’s life.

The prosecution on Monday played a graphic video of the bombing that showed a chaotic, bloody scene with injured people everywhere.

Then, another photo was shown. This time jurors saw Tsarnaev standing by a tree behind the family of Martin Richard.

“These children weren’t innocent to him,” the prosecutor said. “They were American. He knew what that bag was designed to do.”

Chakravarty quoted Bill Richard, Martin’s father, who earlier testified, “I guess we were just unlucky that day.”

“This was a cold, intentional, terrorist act,” he said. The brothers’ acts were intended, he said, “to make a point. To tell America, ‘We won’t be terrorized by you anymore. We will terrorize you.’ “