Jane Flavell Collins, Associated Press
In this courtroom sketch, defense attorney Judy Clarke is depicted addressing the jury as defendant Dzhokhar Tsarnaev, right, sits during closing arguments in Tsarnaev's federal death penalty trial Monday, April 6, 2015, in Boston. Tsarnaev is charged with conspiring with his brother to place two bombs near the Boston Marathon finish line in April 2013, killing three and injuring more than 260 people.

BOSTON — Jurors in the trial of Boston Marathon bomber Dzhokhar Tsarnaev are set to resume deliberations for a second day in the first phase of his federal death penalty trial.

The jury of seven women and five men began deliberations Tuesday on 30 federal charges against Tsarnaev. Jurors will return to U.S. District Court on Wednesday.

During the trial, Tsarnaev's lawyer admitted he participated in the deadly 2013 attack, but said his now-dead brother, Tamerlan, was the mastermind.

If Tsaranev is convicted, the same jury will hear more evidence in a second phase of the trial to decide whether he is sentenced to death or life in prison.

Seventeen of the charges against Tsarnaev carry the possibility of the death penalty.

Three people were killed and more than 260 were injured when twin pressure-cooker bombs exploded near the marathon's finish line on April 15, 2013.

Prosecutors told the jury that Tsarnaev, then 19, and his brother, 26, detonated the bombs to punish the U.S. for its wars in Iraq and Afghanistan.

Tsarnaev's lawyers portrayed him as an aimless teenager who fell under the influence of his radicalized older brother.

Just before dismissing the jury Tuesday, Judge George O'Toole Jr. said he had received two notes from the panel containing questions. He did not reveal the questions, but told the jury he would answer them Wednesday when deliberations resumed.