Katherine Russell Tsarnaev stops co-operating with authorities

Katherine Russell Tsarnaev, the widow of Boston bomber Tamerlan Tsarnaev, has stopped co-operating with authorities as it emerged female DNA found on one of the detonated bombs does not belong to her.

Tamerlan Tsarnaev, 26, who was later killed in a gunfight with authorities, called his wife in the hours after the FBI released surveillance images of him and his younger brother, Dzhokhar.

But only Katherine Russell, 24, knows what was said in the conversation, as she has stopped cooperating with authorities over recent days, the New York Times reported.

Authorities are skeptical of Katherine Russell’s insistence that she played no role in the Boston attack or in helping the Tsarnaev brothers escape the authorities following the release of the photographs, the Times reported.

A source told CNN that the bombs were built in the apartment that Tamerlan Tsarnaev shared with Katherine Russell and their 3-year-old daughter, Zahara. Residue samples were found on the kitchen table, the kitchen sink, and the bathtub, the source said.

Katherine Russell’s silence comes as sources told the newspaper that the fingerprints and female DNA found on at least one of the bombs did not belong to her. Authorities had taken a sample from her this week.

Spokesman Jason Pack confirmed that agents investigating the Boston bombings visited the North Kingstown home of Katherine Russell’s parents, where Tamerlan Tsarnaev’s widow has been staying since the Boston Marathon attacks.