AKIPRESS.COM - A friend of Dzhokhar Tsarnaev appeared in federal court Tuesday on charges related to heroin trafficking as well as possession of a firearm, which is the same model alleged to have been involved in the shooting of MIT police officer Sean Collier.

Stephen Silva, 21, of Memorial Drive in Cambridge, was arrested Monday night and is being held by federal authorities, the Boston Globe reports. 

His charges include conspiracy to distribute heroin this summer. Another charge he faces is the “possession of a firearm with an obliterated serial number.”

According to federal documents, Silva, around February 2013 in Cambridge, two months before the bombing, “knowingly received and possessed a firearm, to wit: A Ruger model P95 9mm pistol, 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.”

A spokeswoman from the US Attorney’s office declined to say whether Silva’s arrest, and the gun that he is accused of possessing, are linked to the Collier’s death. Silva’s court-appointed lawyer, Jonathan Shapiro, said he could not comment on whether Silva’s arrest is linked to the Boston Marathon bombing investigation, because he was just assigned the case Tuesday.

When Tsarnaev was indicted in the summer of 2013, federal authorities said that he and his older brother, Tamerlan, went on the run the night of April 18, 2013, after the FBI published photos of them as the bombing suspects. Authorities said that the brothers were armed with five improvised explosive devices, a Ruger P95 semiautomatic pistol, ammunition, a machete and a hunting knife. It was on that night that they are alleged to have fatally shot Collier in Cambridge and attempted to steal his service weapon.

Tamerlan was killed around 1 a.m. April 19 during a shoot-out with police in Watertown.

Silva was close friends with Dzhokhar Tsarnaev, and was a classmate at Cambridge Rindge and Latin. Stephen Silva’s twin brother, Steven Silva, was even closer to Tsarnaev, as the pair attended high school and UMass-Dartmouth together.

Steven Silva was also close friends with three other UMass-Dartmouth friends of Tsarnaev – Dias Kadyrbayev, Azamat Tazhayakov, and Robel Phillipos – who are charged in federal court with interfering with the bombing investigation. Tazhayakov was convicted Monday of obstruction of justice and conspiracy to obstruct justice for taking a backpack containing fireworks from Tsarnaev’s dorm room on April 18, 2013.

Silva’s stepfather, Tony Gomes, said in a telephone interview Tuesday afternoon that he did not see Stephen Silva last night, but he knows that one of the twins “went to jail” last night, and he believes it was Stephen.

Silva’s next court hearing is scheduled for Aug. 6.