Testimony has ended and closing arguments are expected to start this week in a trial for a friend of Boston Marathon bombing suspect Dzhokhar Tsarnaev.

The Associated Press reported that on Monday, testimony concluded in the trial of Azamat Tazhayakov, who is charged with conspiracy and obstruction of justice.

The Boston Herald noted that the former classmate of Tsarnaev did not testify in his own defense.

Tazhayakov is one of three friends of the bombing suspect who will face trial for interfering with an investigation. Police said Tazhayakov and others allegedly removed a laptop and backpack containing evidence from the suspect’s dorm room in the days after the bombing.

If convicted, he is facing up to 25 years in prison.

Tsarnaev is the sole suspect in the April 15, 2013 bombing that killed three people and injured over 260 others. His older brother, Tamerlan Tsarnaev, was also identified as a suspect but he died in a shootout with police. The younger brother was captured after a major manhunt ensued in and around the city.

The now 20-year-old Tsarnaev is awaiting trial on charges of terrorism.