Investigator's have recovered a DNA sample from Katherine Russell Tsarnaev, the widow of Tamerlan Tsarnaev, after female DNA was discovered on a fragment of the bomb.
Female DNA was discovered on a least one of the Boston bombs, reports said, prompting investigators to begin a further probe into the wife of one of the bombers. Katherine Russell is not considered a suspect in the Boston bombings at the moment.
Russell has been staying with her parents in their Rhode Island home since the bombings occurred. The Russell family had previously stated that they were "shocked" to discover the two men's plot, according to CBS. It is still unclear whether the DNA could lead to an additional female suspect.
"It could have come, for example, from a store clerk who handled materials used in the bombs or a stray hair that ended up in the bomb," FBI officials explained according to a Wall Street Journal report.
An FBI spokesperson declined comment, stating that it was not possible to discuss the details of the case.
"The FBI is there as part of our ongoing investigation, but we aren't permitted to discuss specific aspects of the case," said FBI spokesman Jason Pack.
Russell is one of a many who are of interest to the FBI as the case against Tamerlan and his brother Dzhokhar unfolds. Agents have been posted outside of the Russell's home since the attack. Her lawyer has said she is "doing everything she can to assist with the investigation."
As the case extends, officials are also placing a further look into Tamerlan's visit to Russia from January to July of 2012. It is believed that Tamerlan may have been instructed on how to build bombs and other things while he was aboard.
"Mr. Tsarnaev met several times in early 2012 with Mansur Makhmud Nidal, an alleged militant from the Russian province of Dagestan and suspected jihadist recruiter," the WSJ reported.