(CNN) -- A federal grand jury Thursday charged two friends of Boston Marathon bombing suspect Dzhokhar Tsarnaev with obstructing justice and conspiracy to obstruct justice, the U.S. attorney's office in Boston said. 

Azamat Tazhayakov and Dias Kadyrbayev -- 19-year-old roommates and Kazakh nationals who began attending the University of Massachusetts-Dartmouth the same semester as Tsarnaev -- were charged in May with conspiracy. 

It is not clear whether Thursday's indictment represents a second conspiracy charge. 

Thursday's indictment accuses Tazhayakov and Kadyrbayev of helping Tsarnaev after the April 15 bombing by taking items from his dorm room to keep them from investigators. 

Photos of Tsarnaev released after Rolling Stone complaints 

If convicted, Tazhayakov and Kadyrbayev could be sentenced to a maximum 20 years in prison on the obstruction count and up to five years on the conspiracy count, the U.S. attorney's office said. They also could be fined $250,000. 

Arkady Bukh, Tazhayakov's attorney, said his client is not discouraged. He also said that Tazhayakov did not touch any of Tsarnaev's items. 

"He feels very strongly he'll be able to be able to convince a jury that's he's innocent," Bukh said. "There's no evidence of intent, no incentive to help (Dzhokhar), no motive to destroy anything." 

The three students socialized and texted each other, the indictment says. 

On April 18, three days before the FBI searched Tsarnaev's dorm room, Tazhayakov and Kadyrbayev allegedly went into the dorm, took Tsarnaev's laptop and a backpack containing Vaseline, a thumb drive, fireworks and a "homework assignment sheet" and took them back to their New Bedford apartment, the indictment states. 
WHO WAS CHARGED IN BOSTON?
WHAT IS THEIR RELATION?
HOW OLD ARE THEY?
HOW DID THEY MEET?
WHAT IS TAZAYAKOV AND KABYRBAYEV ACCUSED OF?
WHAT DID THEY DO?
AFTER WHAT INCIDENT DID THAT HAPPEN?
WHO WERE THEY HELPING BY HIDING EVIDENCE?
IF SENTENCED, WHAT IS THE MAXIMUM YEARS IN PRISON THEY WOULD GET?
ANY MONETARY FINES?
WHAT DAY WILL THAT INDICTMENT TAKE PLACE?
WHO IS TAZHAYAKOV'S ATTORNEY?
ACCORDING TO THIS LAWYER, HOW DOES HIS CLIENT FEEL?
ACCORDING TO THE LAWYER, IS THERE ANY EVIDENCE AGAINST HIS CLIENT?
ACCORDING TO THE INDICTMENT, HOW DID THE THREE STUDENTS COMUNICATE?
WHEN DID THEY ALLEGEDLY GO INTO THE DORM ROOM TO HIDE THINGS?
HOW MANY DAYS BEFORE FBI WENT IN FOR SEARCH?
WHAT ITEMS DID THEY SUPPOSABLY TAKE?
WHERE DID THEY TAKE THEM?
Azamat Tazhayakov and Dias Kadyrbayev
Azamat Tazhayakov and Dias Kadyrbayev
roommates
roommates
19-year-old
19-year-old
University of Massachusetts-Dartmouth
University of Massachusetts-Dartmouth
obstructing justice and conspiracy to obstruct justice
obstructing justice and conspiracy to obstruct justice
taking items from his dorm room to keep them from investigators.
by taking items from his dorm room to keep them from investigators. 
Boston Marathon bombing
Boston Marathon bombing
Dzhokhar Tsarnaev
Dzhokhar Tsarnaev
maximum 20 years in prison on the obstruction count and up to five years on the conspiracy count
maximum 20 years in prison on the obstruction count and up to five years on the conspiracy count
$250,000
 $250,000
Thursday
Thursday
Arkady Bukh
Arkady Bukh
that's he's innocent
 that's he's innocent
no
no
socialized and texted
socialized and texted
April 18
 April 18
three days
 three days
laptop and a backpack containing Vaseline, a thumb drive, fireworks and a "homework assignment sheet"
laptop and a backpack containing Vaseline, a thumb drive, fireworks and a "homework assignment sheet"
New Bedford apartment
New Bedford apartment