On Monday, federal authorities took a DNA sample from Katherine Russell, the wife of dead Boston bombing suspect Tameralan Tsarnaev. According to the New York Times, the FBI is attempting to determine whether it matches the female DNA found on one of the bombs detonated during the Boston Marathon.

The Times cites two senior law enforcement sources who say federal authorities are looking into the possibility that Russell helped the Tsarnaev brothers evade capture, plan the attacks or —perhaps unknowingly – destroy evidence.

The focus on Ms. Russell is part of the wider effort by the F.B.I. to determine who else may have played a role aiding the bombers. While the authorities do not believe the bombers were tied to a larger terrorist network or had accomplices, they remain skeptical that others did not know of their plans or did not help them destroy evidence.

Russell has denied any involvement with the attacks and said she was stunned to learn her husband and brother-in-law were suspects. Her lawyer said Russell is “doing everything she can to assist with the investigation.”

[New York Times/Image via AP]