New arrest linked to gun used after Boston bombings

BOSTON (AP) — A friend of Boston Marathon bombing suspect Dzhokhar Tsarnaev is believed to have provided the handgun used to kill a Massachusetts Institute of Technology police officer during the manhunt, people with knowledge of the investigation said Tuesday.

Stephen Silva made an initial appearance in federal court on charges related to heroin trafficking and possession of a handgun with an obliterated serial number. 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.

The 9 mm Ruger pistol described in the indictment is the same handgun that was used to kill MIT police officer Sean Collier during the manhunt for the bombing suspects, according to the two people who spoke on condition of anonymity because they were not authorized to discuss the investigation. Collier's slaying is not mentioned in the grand jury indictment, filed July 15.

According to the indictment, Silva knowingly had possession of the gun, "which had the importer's and manufacturer's serial number removed, obliterated, and altered and had previously been shipped and transported in interstate and foreign commerce."

Silva is a friend of Dzhokhar Tsarnaev. He said in court Tuesday that he graduated from Cambridge Rindge and Latin School in 2011, the same year as Tsarnaev. Silva was ordered to remain in custody ahead of a bail hearing scheduled for Aug. 6.

Dzhokhar's brother, Tamerlan Tsarnaev, was killed in a shootout with police several days after the bombings. Dzhokhar Tsarnaev escaped but was soon found, wounded and hiding in a boat dry-docked in a backyard in suburban Watertown.

Dzhokhar Tsarnaev has pleaded not guilty and is scheduled for trial in November. He faces the possibility of the death penalty if convicted.

Collier, a 26-year-old MIT campus police officer, was shot multiple times in his car.