Dias Kadyrbayev, left, with Boston Marathon bombing suspect Dzhokhar Tsamaev in a picture taken from the social media site VK.com. Kadyrbayev is expected to plead guilty August 21 to charges in connection with removing a backpack and computer from Tsamaev's dorm room after the April 2013 bombing, according to a defense lawyer.
Bombing suspect Tamerlan Tsarnaev was killed during the shootout with police in Watertown, Massachusetts, on April 19, 2013. He is pictured here at the 2010 New England Golden Gloves.
Dzhokhar Tsarnaev was captured in a Boston suburb on April 19, 2013, after a manhunt that shut down the city. In July, he pleaded not guilty to killing four people and wounding more than 200.
From left, Azamat Tazhayakov and Dias Kadyrbayev went with Boston bombing suspect Dzhokhar Tsarnaev to Times Square in this photo taken from the social media site VK.com. A federal grand jury charged Tazhayakov and Kadyrbayev with obstructing justice and conspiracy to obstruct justice relating to the removal of a backpack from Tsarnaev's dorm room after the bombings. Tazhayakov was convicted of conspiracy and obstruction charges in July 2014. He faces up to 25 years in prison at his sentencing in October. He has filed an appeal.
Robel Phillipos, a U.S. citizen, was also arrested on May 1, 2013. He was charged with lying to federal agents about the bombing, according to court papers.
Phillipos, Tazhayakov and Kadyrbayev are accused of removing items from Tsarnaev's dorm room after the bombings on April 15, 2013. The items they took included a backpack containing fireworks that had been "opened and emptied of powder," according to the affidavit.
The FBI released photos and video on April 18, 2013, of two men identified as Suspect 1 and Suspect 2 in the deadly bombings at the Boston Marathon. They were later identified as Dzhokhar Tsarnaev, 19, and his brother Tamerlan Tsarnaev, 26.
Boston Police released surveillance images of Dzhokhar Tsarnaev at a convenience store on April 19, 2013.
The FBI tweeted this photo on April 19, 2013, and urged Watertown residents to stay indoors as they searched for the second suspect.
The FBI released photos and video on April 18, 2013, of two men it called suspects in the deadly bombings and pleaded for public help in identifying them. The men were photographed walking together near the finish line.
A man identified as Suspect 2 appeared in this photograph by bystander David Green, who took the photo after completing the Boston Marathon. Green submitted the photo to the FBI, he told Piers Morgan in an interview.
The man identified as Suspect 2 appears in a tighter crop of David Green's photo.
Authorities later identified Suspect 1 as Tamerlan Tsarnaev.
Suspect 2 was identified as Dzhokhar Tsarnaev.
Suspect 1 walks through the crowd.
Suspect 1 walks through the crowd.
Suspect 1 walks through the crowd.
Both suspects are seen walking through the crowd.
Suspect 2 walks through the crowd.
Suspect 2 walks through the crowd.
A photo released by the FBI highlights Suspect 2.
A photo released by the FBI highlights Suspect 2.
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
Suspects tied to Boston bombings
STORY HIGHLIGHTS
- The three men are friends of surviving Boston bombing suspect Dzhokhar Tsarnaev
- Each is accused of removing items from Tsarnaev's dorm room after the April 15 attack
- A friend of one of the men describes him as a "good kid" who "never got in trouble"
(CNN) -- The number of people potentially embroiled in the Boston Marathon bombings case grew Wednesday to include friends of surviving suspect Dzhokhar Tsarnaev.
Not much is known yet about the three 19-year-old men -- Azamat Tazhayakov, Dias Kadyrbayev and Robel Phillipos.
But here is what CNN has learned so far.
All started at the University of Massachusetts-Dartmouth in 2011, along with Tsarnaev.
Each is accused of removing items from Tsarnaev's dorm room after the April 15 attack, which killed three people and wounded more than 260.
FBI details how suspect's friends trashed evidence
Father: My son is 'not implicated'
The case against Tsarnaev's friends
Giuliani: Friends' silence deadly
3 accused of Boston bombing cover-up
Azamat Tazhayakov
Tazhayakov was already in federal custody before Wednesday on immigration charges. He is from Kazakhstan and had a student visa.
According to the University of Massachusetts-Dartmouth, Tazhayakov is enrolled, but was suspended pending the outcome of the case.
He is charged with obstruction of justice. If found guilty, he could face up to five years in prison and $250,000 in fines.
Harlan Protass, who represents Tazhayakov, said his client "has cooperated fully with the authorities and looks forward to the truth coming out."
Dias Kadyrbayev
Kadyrbayev is likewise a Kazakh national and charged with obstruction of justice.
Similar to Tazhayakov, he could face up to five years in prison and $250,000 in fines if found guilty.
The two men share an apartment in New Bedford, Massachusetts.
Kadyrbayev's lawyer, Robert Stahl, said his client "did not have anything to do" with the bombing and disputed that he tried to block the investigation.
Kadyrbayev was taken into custody along with Tazhayakov last month on suspicion that he had violated the terms of his student visa, according to Stahl.
He said Kadyrbayev was accused of a "technical violation" for failing to attend classes on a regular basis.
Kadyrbayev is not currently enrolled at the University of Massachusetts-Dartmouth.
According to an interview his father gave last week, the 19-year-old "missed a couple, or maybe several classes."
"I can say about my son that he finished school with excellent grades; he was good at math. He helped others. When he saw that help was needed, he always accommodated," Murat Kadyrbayev told Tengi News and STV channel in Kazakhstan.
Timeline: Bombing, manhunt and more
Robel Phillipos
Unlike Tazhayakov and Kadyrbayev, Phillipos is a U.S. citizen.
Like Kadyrbayev, he is not a current student at the University of Massachusetts-Dartmouth.
Phillipos attended high school with Tsarnaev at Cambridge Rindge and Latin School in Cambridge, Massachusetts, where they both live.
A yearbook photograph shows a smiling Phillipos. Almost directly in front of him, Tsarnaev stares at the camera -- his hand gently resting under his chin.
Phillipos is charged with lying to federal agents investigating the bombing. He faces up to eight years in prison if convicted, along with a $250,000 fine.
A friend described Phillipos as a "good kid."
"He went to school, never got in trouble, took care of his mom," James Turney told CNN affiliate WBZ. "He was not really outgoing, stayed in the house a lot, did homework, got good grades."
Phillipos plays basketball and doesn't have "any anti-American thing about him," Turney said.
"It just doesn't make sense. Robel doesn't have anything to do with this, or what happened, so I don't see why he's being arrested," he told WBZ.
CNN's Matt Smith, Tom Watkins, Susan Candiotti, Deborah Feyerick, Gloria Borger, Carol Cratty, Jake Tapper, Brian Todd, Pamela Brown and Kathleen Johnston contributed to this report.