A man believed to have provided the gun used by Boston Marathon bombing suspects to kill a college police officer has been arrested on drug and weapon charges.
Stephen Silva made an initial appearance in federal court Tuesday on charges related to heroin trafficking and possession of a handgun with an obliterated serial number.
Two people with knowledge of the investigation say the gun is the one that was used to kill Massachusetts Institute of Technology police officer Sean Collier during the manhunt for bombing suspects Dzhokhar and Tamerlan Tsarnaev.
The people spoke on condition of anonymity because they were not authorized to discuss the investigation.
Silva is a friend of Dzhokhar Tsarnaev who graduated from Cambridge Rindge and Latin School with him in 2011.
An attorney for Silva, Jonathan Shapiro, said Tuesday evening that he received the case only a few hours earlier and was not in a position to comment.