BOSTON : The American student accused of carrying out the 2013 Boston marathon bombings that killed three and injured 264 others went on trial Wednesday.

Dzhokhar Tsarnaev, 21 - who was born in Kyrgyzstan to a Chechen family but grew up in the United States - faces the death penalty if convicted of bombing Boston's signature race.  Several survivors were in the packed courtroom, among them the parents of Martin Richard, an eight-year-old boy who was killed. Tsarnaev, who obtained American citizenship in 2012 after living in the United States since 2002, is accused of carrying out the bombings with his elder brother, Tamerlan. The 26-year-old Tamerlan was killed in a shootout with police, leaving the younger Tsarnaev to face charges for attacks that devastated the northeastern US city of 645,000.

He has pleaded not guilty to 30 federal charges in connection with the attacks and the killing of a police officer while he and his brother were on the run.