Azamat Tazhayakov is the first of Tsarnaev's friends to face trial. He is charged with removing evidence from Tsarnaev's room at the University of Massachusetts Dartmouth and throwing away a backpack containing fireworks casings as the FBI searched for the suspect, who is accused of killing three people and injuring 264 in the April 2013 bombings.
FBI Special Agent Timothy Quinn said Tazhayakov told him that Tsarnaev had discussed martyrdom and his knowledge of bomb building during a conversation over lunch with Tazhayakov and his roommate and fellow Kazakh exchange student Dias Kadyrbayev before spring break last year.
"Dzhokhar had explained that people who die in an act of martyrdom die with a smile on their face and go straight to heaven," said Quinn, who interviewed Tazhayakov in the days after the alleged visit to Tsarnaev's room.
"He also explained that during the same conversation, Dzhokhar said he knew how to build bombs" because he had taken chemistry classes, Quinn testified.
Tsarnaev was captured in the days after the bombing and is awaiting trial, but his older brother Tamerlan, also a suspect in the bombing, was killed following a shoot-out with police.
On Thursday (local time), another FBI agent, Farbod Azad, testified that Tazhayakov told him he and Kadyrbayev, and a third man, Robel Phillipos of Cambridge, Massachusetts, had removed the backpack and a laptop from Tsarnaev's dorm room.
Azad questioned Tazhayakov after the three were ordered out of their New Bedford, Massachusetts, apartment by heavily armed agents. Tazhayakov's attorneys have argued their client's statements during that interview should not be admitted at trial because he had not believed he was free to go at the time.
Tazhayakov could face up to 25 years in prison if convicted of obstruction of justice and conspiracy. Kadyrbayev faces the same charges. Phillipos is accused of the lesser charge of lying to investigators.
None of the three friends are charged with playing a role in the bombing.
Trials for Kadyrbayev and Phillipos are scheduled for later this year.
Tsarnaev is awaiting trial, set for November, on charges that carry the death penalty if he is convicted.
