Katherine Russell Tsarnaev’s new lawyer, Joshua Dratel, insists that the Boston Marathon bombing suspect’s widow will co-operate with the investigation into the terrorist atrocity.

Joshua Dratel, who has represented several terrorism suspects, joined the legal team of Katherine Russell, who was married to Tamerlan Tsarnaev, last week.

Katherine Russell has not been accused of any wrongdoing, but the FBI are currently interrogating her to find out if she had any clue as to her husband’s plans.

The bombing at the marathon’s finish line on April 15 killed three people and injured more than 260.

Katherine Russell Tsarnaev’s new lawyer Joshua Dratel insists that she will co-operate with the investigation into the terrorist atrocity

Tamerlan Tsarnaev, 26, and his younger brother Dzhokhar, originally from Chechnya, are believed to have carried out the attacks due to their radical jihadist beliefs.

Joshua Dratel, from New York, today said that he joined Katherine Russell’s legal team to help her navigate the criminal justice system and to protect her interests.

He said she had spoken with investigators and planned to keep co-operating.

“I don’t see that changing in the foreseeable future,” he said.

“There’s no inconsistency between that and her interests at this point.”

Dzhokhar Tsarnaev, 19, is in a prison hospital facing charges that could bring the death penalty. Tamerlan Tsarnaev died on April 19 after a shootout with police.

Katherine Russell, 24, had been living in Cambridge, Massachusetts with her husband and two-year-old daughter, but has been staying with her parents in North Kingstown, Rhode Island, since the day her husband was killed.

She has reverted to using her maiden name, switching from her married name of Tsarnaeva.

Among the questions about Katherine Russell is what she knew or saw in the weeks leading up to the bombing, and in the days after it.

Two U.S. officials have said that Dzhokhar Tsarnaev told investigators the bombs were assembled in the small apartment Katherine Russell shared with her husband.

One of her lawyers has previously said Katherine Russell was working long hours and was frequently away from the apartment.