Female DNA and fingerprints found on fragments of the Boston Marathon bombs don't match suspect Tamerlan Tsarnaev's widow, according to law enforcement officials.
Katherine Russell stopped cooperating with investigators within the last few days, the New York Times reported Friday. That's a change from what Russell's lawyer, Amato DeLuca, said Tuesday.
"In the coming days, Katherine will continue to meet with law enforcement, as she has done for many hours over the past week, and provide as much assistance to the investigation as she can," DeLuca said in a statement Tuesday.
DeLuca said Russell had been interviewed by the FBI several times at the agency's Providence field office. She has been staying at her parents' house in North Kingstown, R.I., since Tsarnaev was killed during a police shootout.
On Monday, investigators obtained DNA samples from Russell and took other evidence from her family's home.
The Times cited law enforcement sources who said Russell's fingerprints and DNA did not match genetic material discovered on parts of the marathon bombs, which were made from pressure cookers.
Three people were killed an 264 others hurt when the brothers allegedly set off two explosions at the Boston Marathon finish line on April 15.
The Tsarnaevs had planned to detonate the explosives during Boston's 4th of July festivities, but finished making the bombs early, according to reports Friday.
ABC News reported that Tsarnaev called Russell after the FBI released photos of the suspects three days later, just hours before the brothers allegedly killed an MIT police officer and carjacked a man, leading to the confrontation with police. Investigators want to know what Tsarnaev and Russell talked about.
Tsarnaev's body was claimed from the Massachusetts medical examiner's office Thursday. A cause of death has been determined and could be made public as early as Friday.
The other marathon bombing suspect, 19-year-old Dzhokhar Tsarnaev, is being held at a prison at Fort Devens, charged with using a weapon of mass destruction.
Three of his friends from the UMass Dartmouth are charged with removing evidence from Tsarnaev's dorm room and lying to investigators.
Follow Metro Boston on Twitter: @MetroBos