Boston Marathon bombing investigators find new, female DNA evidence

Authorities involved in the ongoing investigation of the Boston Marathon attacks have identified female DNA on pieces of explosives used in the incident, though investigators caution against jumping to conclusions.

Word of the new DNA evidence came on the same day that FBI agents visited the home of Tamerlan Tsarnaev’s widow’s parents in suburban Providence, Rhode Island. That residency is where the bombing suspect’s widow, Katherine Russell, and her three-year-old daughter have been staying since the eldest Tsarnaev brother was revealed to be a suspect in the attack and was subsequently killed during a shootout with Boston police.

A lawyer representing Russell stated that she is actively cooperating with the investigation. As the Wall Street Journal reports, FBI officials have been negotiating with her lawyer for full access to question Russell, though she has not been named a suspect in the April 15 bombing.

Officials confirmed that agents collected a DNA sample from Russell after days of negotiations, which they say will be analyzed for a match with DNA recently found on the bomb parts.

FBI agents spent several hours at the home of Russell's parents, emerging with bags marked as DNA samples, a person familiar with the case told Reuters. Russell and Tamerlan Tsarnaev lived with their daughter in Cambridge, Massachusetts, and police are known to have found bomb elements in their home.

According to Russell’s lawyers, she was unaware of 26-year-old Tamerlan Tsarnaev’s radicalization as she spent the majority of her time working as a health aide, while her husband stayed at home watching their daughter.

Since the deadly shootout that killed the eldest Tsarnaev there as been speculation as to the exact cause of his death, as he was hit by police gunfire and then run over in a car by his younger brother, Dzhokhar, who was fleeing the scene.

A spokesman for the Massachusetts Office of the Chief Medical Examiner, Terrel Harris, announced on Monday that the cause of death has been determined, though no findings will be made public until the body is claimed and a death certificate filed. No one has yet claimed Tsarnaev's body.

It was thought at one point that the brothers’ parents, who currently reside in Russia, would be traveling to the US to claim their son’s body, though they announced on Sunday that this would not be the case. As RT previously reported, the mother of the Boston Marathon bombing suspects, Zubeidat Tsarnaev, had been added to a federal terrorism database - the Terrorist Identities Datamart Environment database or TIDE - about 18 months before the attack. That information came shortly after she publicly accused US police of murdering her son.

The medical examiner’s office has stated that Ms. Russell would be permitted to claim Tamerlan.

Younger brother Dzhokhar, meanwhile, continues to recover at a prison medical center since sustaining bullet wounds during his capture by police on April 19.

Officials familiar with the case have told the Wall Street Journal that the newly identified female DNA could be attributed to any number of sources, and does not necessarily indicate additional accomplices. The genetic material could have shown up due to a stray hair, perhaps, or from a store clerk who previously handled the bomb materials, which included an easily obtainable pressure cooker.