Tsarnaev Brothers
Did a woman help out the Tsarnaev brothers? FBI

Female DNA was found on at least one of the explosives used in the Boston Marathon bombings, but it’s too soon to determine whether the discovery means that a woman handled the bomb or helped the two brothers suspected of carrying out the bombings.

Authorities have yet to determine whose DNA is on the bomb, the Wall Street Journal reported Monday, citing officials briefed on the investigation into the attacks.

The sources cautioned that just because DNA was found on at least one of the bombs, it doesn’t necessarily mean that a woman is an additional suspect in the April 15 attacks. For instance, the DNA could belong to a clerk from whom the Tsarnaev brothers purchased bomb materials. It could also be from a stray hair that somehow ended up inside the bomb, according to the Journal.

The revelation of the discovery of the DNA came as FBI agents were leaving the home of Katherine Russell, wife of dead Boston bombings suspect Tamerlan Tsarnaev.

Agents were in the home to take a DNA sample from Russell following days of negotiations between the widow, her attorney and federal officials, the Journal reported. The sample was requested to see if it matched DNA found on pieces of the exploded bomb.

Tsarnaev, 26, died in a shoot-out with authorities two weeks ago -- the same day the FBI appealed to the public for assistance in apprehending the two then-unnamed suspects in the Boston bombings.

Tsarnaev’s younger brother, 19-year-old Dzhokhar Tsarnaev, eluded authorities for much of the day on April 19. He was eventually found hiding in a boat in a backyard in Watertown, Mass., shortly after an order to for the public to take shelter in place was lifted by authorities.

Since the bombings, Russell has been staying with her parents, and FBI agents have been posted outside the home, according to the Journal. Her attorney said she is “doing everything she can to assist with the investigation.”

Dzhokhar Tsarnaev was arraigned last week on two terrorism-related charges and was transferred Friday from Beth Israel Deaconess Medical Center in Boston to a federal jail. His next court hearing is scheduled for late next month.

The investigation into the bombings has so far led authorities to believe that the Tsarnaevs carried out the attack on their own and used the Internet to research how to make the bombs that exploded near the finish line of the Boston Marathon.

There was concern that the elder Tsarnaev had been radicalized, with his uncle, Ruslan Tsarni, placing blame on a Boston-area Muslim he knew as “Misha.”

But “Misha,” or Mikhail Allakhverdov, has not been linked to the bombings or to terrorism in general, according to the Associated Press.

In an interview with the New York Review of Books, Allakhverdov said he knew Tamerlan Tsarnaev but had no contact with the 26-year-old in three years. He also said he would have steered Tamerlan clear of radical Islam or committing the attacks.

“I wasn’t his teacher," he said. "If I had been his teacher, I would have made sure he never did anything like this."