Three of Dzhokhar Tsarnaev's friends have been accused of covering for the bombing suspects.
Azamat Tazhayakov and Dias Kadyrbayev, both from Kazakhstan, were charged Wednesday with conspiring to discard potentially incriminating items from Dzhokhar Tsarnaev's dorm room. Robel Phillipos, a U.S. citizen, was charged with making false statements to investigators.
All three are accused of removing items from Tsarnaev's dorm room after the bombings. According to FBI affidavits released this week, they left with the backpack and Vaseline -- which Tazhayakov believed could be used to make bombs -- and Tsarnaev's laptop.
Investigators found the backpack, fireworks and Vaseline in a landfill last week after a two-day search.
The laptop was turned over by Kadyrbayev on April 19, the same day the FBI raided the apartment he shared with Tazhayakov, Kadyrbayev's attorney Robert Stahl said.
The FBI is examining the laptop, two federal law enforcement officials told CNN.
Authorities have said they believe the Tsarnaev brothers acted alone but are investigating whether they could have learned from or been aided by terror groups, including groups overseas.