Dzhokhar Tsarnaev with his close friends, identical twins Stephen (left) and Steven Silva. Stephen Silva is now charged with dealing drugs and possessing the gun that prosecutors said the Tsarnaevs brothers fired 56 times in the days after the deadly blasts. The Silvas graduated from Cambridge Rindge and Latin with Tsarnaev and worked with him at the Harvard University pool as lifeguards, officials said. Stephen also told police "I smoke weed...because my best friend is the bomber," during an unrelated arrest on drug charges in Nov. 2013, according to a MBTA police report.&nbsp;