Boston Marathon bombing suspect Dzhokhar Tsarnaev told a friend a month before the deadly attack that he knew how to make a bomb and said it’s good to be a martyr because you “die with a smile on your face and go straight to heaven,” a federal prosecutor told jurors Monday at the friend’s obstruction trial.

Tsarnaev also texted the friend, Azamat Tazhayakov, 90 minutes after the bombings and said, “Don’t go thinking it’s me,” Assistant U.S. Attorney Stephanie Siegmann said.

Siegmann’s comments came during opening statements at Tazhayakov’s trial, a prosecution that promises to provide a glimpse into the government’s case against Tsarnaev.

Tsarnaev is scheduled to go on trial in November on charges that carry the possibility of the death penalty. Prosecutors say he and his older brother, Tamerlan, built two bombs and placed them near the finish line of the 2013 marathon to retaliate against the U.S. for its actions in Muslim countries. The explosions killed three people and injured more than 260. Tamerlan Tsarnaev died following a shootout with police several days later.

Tazhayakov, 20, has pleaded not guilty to obstruction of justice and conspiracy charges. He and his roommate, Dias Kadyrbayev, went to Tsarnaev’s University of Massachusetts-Dartmouth dorm room several days after the bombing and took a laptop computer and a backpack containing fireworks that had black powder spilling out or had been emptied of their powder, Siegmann told the jury.

“The government will prove to you that the defendant and his co-conspirator removed the backpack for one reason, and that reason was to protect their friend who they had just learned was one of the two suspected marathon bombers,” Siegmann said.

Prosecutors acknowledge that Kadyrbayev is the one who actually put the backpack in the trash but said Tazhayakov agreed to get rid of it.

She described a conversation Tsarnaev had with Tazhayakov and Kadyrbayev a month before the bombings while they ate together at a restaurant.

“Tsarnaev told the defendant and Kadyrbayev that it was good to die as a shaheed, or a martyr, as you would die with a smile on your face and go straight to heaven,” she said.

During that same meal, Siegmann said, Tsarnaev also told his friends he knew how to make a bomb and went on to list the ingredients, including gunpowder or explosive powder like what was found in the fireworks inside the backpack.

Tazhayakov’s defense attorney, Nicholas Wooldridge, urged jurors not be swayed by the emotional impact of the marathon bombings. He asked them instead to focus on Tazhayakov’s actions.

“Azamat’s actions will show that he never intended to obstruct justice. As a matter of fact, he never intended to help the bomber himself,” Wooldridge said.

As the lawyers outlined their cases to the jury, the mother of two men who each lost their right leg in the bombings listened in court. Liz Norden declined to comment afterward.

Wooldridge said Tazhayakov went to Tsarnaev’s dorm room with Kadyrbayev three days after the bombings and hours after the FBI released video footage and photos of the brothers.

But he said Tazhayakov watched a movie while Kadyrbayev looked around Tsarnaev’s room after receiving a text from Tsarnaev that said, “If you want, you can go to my room and take what’s there,” followed by a smiley face, which Wooldridge said was a symbol that meant marijuana to the friends.

Wooldridge said it was Kadyrbayev who threw the backpack away in the trash after his girlfriend learned it belonged to Tsarnaev and told him, “Get it out of the apartment.”

“Azamat never even touched that bag,” Wooldridge said.

Kadyrbayev’s girlfriend is expected to testify against Tazhayakov under a grant of immunity from prosecutors.

Kadyrbayev faces his own trial in September.

(AP)