Attorneys recently filed change of venue motions for Dias Kadyrbayev, Azamat Tazhayakov and Robel Phillipos, who used to attend the University of Massachusetts Dartmouth with Tsarnaev. The three are set to appear in court this week starting on Tuesday, where they are expected to testify.
Kadyrbayev and Tazhayakov are Kazakhstan nationals who are charged with tampering with evidence for removing Tsarnaev's laptop and a backpack containing fireworks from his college dorm room shortly after last year's fatal bombing. Kadyrbayev also faces conspiracy and obstruction of justice charges. He and Tazhayakov have been held without bail for more than a year.
Phillipos, of Cambridge, is accused of lying to investigators and wants his case to be tried separately. He has been held under house arrest.
They have all pleaded not guilty. Their trial is scheduled to begin on June 30.
Their lawyers say because of overwhelming media coverage of the case their clients won't receive fair trials in Massachusetts. But prosecutors are opposed to any change.
Tsarnaev, 20, has pleaded not guilty to 30 federal charges in the April 15, 2013, bombing that killed three people and injured more than 260. He and his older brother Tamerlan Tsarnaev, 26, allegedly placed two pressure cooker bombs near the Marathon finish line. Three days later Tamerlan was killed in a gun battle with police, the same night Massachusetts Institute of Technology security officer Sean Collier was also shot and killed.
Dzhokhar Tsarnaev is facing state charges in Collier's death.
Federal prosecutors are seeking the death penalty in the trial that is set to begin in November.