An investigator carries an evidence bag off a roof top near the site of two explosionReuters

A man who lent the Boston Marathon bombers the gun they used to kill a police officer three days after the 2013 attack is due in court on Tuesday to be sentenced for drug and firearms charges.

Stephen Silva was not accused of playing any role in the April 15, 2013, bombing, which killed three people and injured 264, but he pleaded guilty last year to drug charges and to having possessed a handgun with its serial number filed off.

He testified in March that he lent that gun, a Ruger P95, to Dzhokhar Tsarnaev, who told him he wanted it to rob college students in Rhode Island.

Tsarnaev was found guilty in April of carrying out the bombing attack along with his older brother as well as shooting dead Massachusetts Institute of Technology police officer Sean Collier, 27, three days later. Tsarnaev's older brother, 26-year-old Tamerlan, died following a gunfight with police later that night.


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Silva, who had been a high school friend of the younger Tsarnaev's pleaded guilty under the terms of deal with federal prosecutors filed under seal in U.S. District Court in Boston. He could face a sentence of up to 40 years in federal prison for the most serious charge, conspiracy to distribute heroin.

Prosecutors argued in court papers filed last month that Silva should face a stiff sentence for having used a firearms in his heroin and marijuana dealing.

"The terrible facts of this case exemplify, in its starkest terms, the danger addressed by the firearm enhancement - the combination of drug trafficking and gun possession," they wrote. "The Ruger was then used to kill a police officer in connection with one of the worst acts of terrorism in the history of Massachusetts."

Defense lawyers noted that Silva had already given the gun to Tsarnaev by the time of the drug dealing that led to the charges, when he sold heroin to a government informant in 2014 as investigators were probing his ties to the Tsarnaev brothers.

"The government orchestrated Mr. Silva’s involvement...for the purpose of developing information that could be used in the prosecution of Tsarnaev," defense attorneys wrote.

Tsarnaev has been sentenced to death by lethal injection, a sentence his attorneys are appealing.

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