Actually, they may not have, after all. I just scanned thru Special Agent Cieplik's affidavit. It states that they recovered the backpack from the landfill and found the emptied fireworks, a jar of Vaseline, and a UMass homework assignment sheet for a class Tsarnaev was taking. No mention of the computer being recovered, although it does state that the accused did take the computer from Tsarnaev's dorm room.
“fireworks, a jar of Vaseline, and a UMass homework assignment”
Just heard part of Wolf Blitzer having a big discussion about Vaseline as a bomb ingredient! Heh.
A group of young muzzie boys and a jar of Vaseline?
In addition to bomb making, I suspect they were covering up other activities also!