BOSTON — A federal jury was set to begin a second day of deliberations today in the trial of a man accused of trying to protect Boston Marathon bombing suspect Dzhokhar Tsarnaev during the investigation into the deadly attack.

Tsarnaev’s friend Azamat Tazhayakov is accused of agreeing with another friend, Dias Kadyrbayev, to take a backpack containing opened fireworks and other items from Tsarnaev’s college dorm room and is charged with obstruction of justice and conspiracy.

The jury began deliberating Wednesday after hearing closing arguments from prosecutors and Tazhayakov’s lawyer.

Assistant U.S. Attorney John Capin told the jury Tazhayakov and Kadyrbayev removed a backpack containing fireworks that had been emptied of their gunpowder and other items from Tsarnaev’s room hours after the FBI released images of Tsarnaev and his brother as suspects in the 2013 marathon attack, in which two bombs exploded near the finish line, killing three people and injuring more than 260.

Capin said Tazhayakov became “scared” when he saw fireworks that had been emptied of gunpowder in Tsarnaev’s backpack because Tsarnaev had told him and other friends weeks before the marathon bombings that gunpowder is one of the ingredients needed to make a bomb.

Capin said that when Kadyrbayev found a jar of Vaseline, he told Tazhayakov, “This is what he uses to make bombs.” The Vaseline was later found in Tsarnaev’s backpack when agents recovered it in a landfill.

“That agreement to take items out, to remove items because they suspected he was the bomber, that is a conspiracy to obstruct justice,” Capin told the jury.

But Tazhayakov’s lawyer, Matthew Myers, said he was a naive college kid who was prosecuted because he was a “friend of the bomber.”

“He’s a friend of a kid who committed a heinous act, and friends of bombers are enemies of ours,” Myers said. “Guilt by association ”“ that’s exactly what this case is about.”

Myers said Tazhayakov and another friend, Robel Phillipos, sat passively watching a movie in Tsarnaev’s dorm room as Kadyrbayev took the backpack. Myers said Kadyrbayev decided to throw away the bag after his girlfriend ordered him to “get it out of the apartment.”

Kadyrbayev will be tried separately in September. Phillipos, who is charged with lying to investigators, also faces a separate trial.

Tsarnaev is awaiting a November trial and faces the possibility of the death penalty if convicted.

The defendants have pleaded not guilty.

Prosecutors allege Tsarnaev and his brother, Tamerlan Tsarnaev, carried out the bombings and killed a Massachusetts Institute of Technology police officer days later.

Tamerlan Tsarnaev died following a shootout with police the night the officer was killed. Dzhokhar Tsarnaev was captured hiding in a boat in a Watertown backyard.