World Bulletin / News Desk 

Two friends of convicted Boston Marathon bomber Dzhokhar Tsarnaev will learn on Friday how long they will spend in prison for having removed a backpack containing fireworks from the suspect's room during a massive manhunt.

Azamat Tazhayakov and Robel Phillipos, of Cambridge, Massachusetts, joined a third friend and fellow student in going to Tsarnaev's dorm room three days after the April 2013 bombing, after the FBI released images of Tsarnaev and his older brother, Tamerlan, identifying them as suspects.

The third friend, Dias Kadyrbayev, also of Kazakhstan, was sentenced on Tuesday to six years in prison after pleading guilty to obstructing the investigation into the attack that killed three people and injured 264. Prosecutors had sought a sentence of seven years.

Before he was sentenced, Kadyrbayev apologized for his actions, saying, "I know my bad decision put shame on my name."

Prosecutors are seeking a four-year sentence for Tazhayakov, well below the maximum of 25 years allowed by law, which they said reflected his willingness to testify at Tsarnaev's trial. A federal jury found Tazhayakov guilty of obstruction of justice.

Phillipos, who was found guilty of the lesser charge of lying to investigators, could face up to eight years in prison.

The pair, both of whom were 19 at the time of the attacks, will be sentenced in separate hearings in federal court in Boston.

All three men, along with Tsarnaev, were students at the University of Massachusetts at the time of the bombing. Tazhayakov and Kadyrbayev were roommates at the time.

Michael Dukakis, the former Massachusetts governor and 1988 Democratic presidential candidate, who is a friend of the Phillipos family, urged leniency in a Wednesday letter to U.S. District Judge Douglas Woodlock filed to the court.

"Robel is a young man who could and should have a great future ahead of him," Dukakis wrote. "For the life of me, I can't understand why justice would be served by incarcerating him."