Accused Boston Marathon bomber Dzhokhar Tsarnaev sat quietly in court, occasionally touching his face as jury selection began for his trial.

Tsarnaev, a 21-year-old ethnic Chechen who is a naturalized U.S. citizen, could get the death penalty if convicted of killing three people and injuring more than 260 others by detonating a pair of homemade bombs placed amid a crowd of thousands of spectators at the race's finish line on April 15, 2013. He has pleaded not guilty to all 30 charges against him.

U.S. District Judge George O'Toole acknowledged the panel of 12 jurors and six alternates will be aware of the incident, but reminded the group that their job during the three to four month trial would be to consider only the evidence presented in court.

O'Toole signaled that he would allow about three weeks for selection of the jury from a pool of about 1,200 and said opening statements in the case will begin around the end of January.