A US jury has returned the first conviction over the 2013 Boston Marathon attacks, finding a friend of the prime suspect guilty of obstructing the investigation into the bombings.

Azamat Tazhayakov, 20, was convicted of obstruction and conspiracy over taking a backpack from alleged bomber Dzhokhar Tsarnaev’s college dorm room in the days after the attacks.

He faces up to 20 years in prison when sentenced on October 16, although legal experts say he could be deported straight away or serve as little as three years before being deported.

The seven men and five-women jury returned the verdict against the student from Kazakhstan after deliberating less than two full days following a two-week trial in a court in Boston.

He is the first of three former students to stand trial, accused of interfering with the investigation to protect Dzhokhar Tsarnaev while he was on the run from the FBI.

Twin bombs planted at the marathon finish line killed three people and injured 264 on April 15, 2013, in an attack allegedly carried out by Chechen brothers Dzhokhar and Tamerlan Tsarnaev.

Dzhokhar is due to stand trial in November – he is accused of 30 federal charges and could face the death penalty if convicted.

Police shot dead his older brother Tamerlan after the attacks.

Tazhayakov showed no emotion whatsoever when Monday’s verdict was read out, but his mother sobbed loudly from the gallery.

US Attorney Carmen Ortiz thanked members of the government team and the jury for securing the conviction.

“I want to thank the jury for their careful attention and services in this matter,” she told reporters.