A close friend of Dzhokhar Tsarnaev, the surviving suspect in the Boston Marathon bombing case, appeared in federal court Tuesday on charges of heroin trafficking and possessing a Ruger pistol in early 2013, the same model alleged to have been used in the shooting of MIT police Officer Sean Collier days after the bombings.
The US attorney’s office in Boston, which brought the charges, declined to say if the arrest of Stephen Silva, 21, who went to Cambridge Rindge and Latin with Tsarnaev and worked alongside him as a lifeguard at the Harvard University pool, is related to the Boston Marathon bombing investigation. Details of the gun case remain unknown, and law enforcement officials would not comment.
A grand jury indicted Silva a week ago; however, he was not arrested until Monday night at his family’s Cambridge apartment.
He is being held by federal authorities and is due back in court Aug. 6.
Most of the charges against Silva relate to conspiracy to distribute heroin and cite six dates last month when he allegedly possessed and attempted to sell the drug in Medford.
One charge, however, focuses on Silva’s alleged “possession of a firearm with an obliterated serial number” in Cambridge in February 2013, two months before the bombing.
According to federal documents, Silva “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.”
Federal investigators have said that when Tsarnaev and his older brother, Tamerlan, were on the run the night of April 18, 2013, after the FBI published photos of them as the bombing suspects, they were armed with five improvised explosive devices, a Ruger P95 semiautomatic pistol, ammunition, a machete, and a hunting knife. On that night, the brothers fatally shot Collier in his patrol car in Cambridge and attempted to steal his service weapon, police say.
Tamerlan was killed hours later, in the early morning of April 19, during a shootout with police in Watertown. The Ruger pistol was recovered at the scene.
According to a Los Angeles Times article published in May, investigators were ultimately able to discern the gun’s serial number, even though attempts had been made to obliterate it.
Based on that, authorities traced the gun’s original purchase to a store near Portland, Maine, and to two people with alleged criminal ties. The article did not explain how authorities believe that the gun got from Maine to the Tsarnaev brothers in Massachusetts.
Jonathan Shapiro of Boston, appointed Tuesday as Silva’s lawyer, said he could not comment on whether Silva’s arrest is linked to the bombing investigation because he was not yet familiar with the case.
Stephen Silva’s twin brother, who has a very similar name, Steven Silva, is widely identified as one of Dzhokhar Tsarnaev’s closest childhood friends, and the pair attended Cambridge Rindge and Latin and the University of Massachusetts Dartmouth together. The twins apparently both attended the University of Massachusetts Boston in the past year.
Steven Silva was also close friends with three UMass Dartmouth friends of Tsarnaev: Dias Kadyrbayev and Azamat Tazhayakov, who are charged in federal court with interfering with the bombing investigation, and Robel Phillipos, who is charged with lying to investigators.
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.
Kadyrbayev is scheduled to go to trial in early September, and Phillipos’s trial is slated for late September.
The Silvas and Phillipos grew up in the same apartment complex in Cambridge.
The twins’ stepfather, Tony Gomes, said by phone Tuesday afternoon that he was not aware of the details of Monday’s arrest.
He said he did not see Stephen Silva Monday night, but knows one of the twins “went to jail,” and he believes it was Stephen.
At the apartment complex where Silva used to live, residents spoke about the arrest.
“I saw lots of FBI guys here last night,” said one who declined to give his name. “They had some empty boxes with them, maybe to confiscate something.”
He said four or five officers were standing in the lobby last night at 8:30, with a Cambridge drug officer among them. He also said drugs were a common presence.
A resident of the adjoining apartment complex, who also did not want his name published, said Stephen Silva was a loyal friend.
“He was a pretty cool guy, relaxed, and he’d mind his own business,” the 16-year-old said.
He said officers swarmed the building Monday night, many of them in plain clothes and driving undercover vehicles.
“They rolled in at least 16 cars deep,” he said. “All you hear are car tires screeching.”
He said officers carried out items in large containers, including a scale.
Two women in the complex’s tenants association, who declined to give their names, said the building was a “nice community.”
Globe correspondent Clair McNeill contributed to this report. Patricia Wen can be reached at patricia.wen@
globe.com, and Milton J. Valencia at milton.valencia@