Investigators have found female DNA on a fragment from one of the two bombs used in the attack on the Boston Marathon two weeks ago, according to a U.S. official briefed on the probe.
The genetic material may have come from a number of sources and its discovery doesn't necessarily mean that additional people were involved beyond the two brothers suspected in the bombing, said the official, who asked not to be identified in discussing an ongoing case.
The DNA find emerged as authorities continue to investigate whether the suspects, Tamerlan and Dzhokhar Tsarnaev, had help in planning or carrying out the April 15 attack. So far, according to a second U.S. official who asked not to be identified, there's no evidence of such assistance.
Among those under scrutiny is Katherine Russell Tsarnaev, whose husband Tamerlan was killed in an April 19 shootout with police. Agents from the Federal Bureau of Investigation were at her home as part of the probe, Jason Pack, an agency spokesman, said in an e-mail. He declined to comment further, saying the bureau can't discuss specific aspects of the case.
The Russell family's lawyer, Amato DeLuca, said last week that Katherine Tsarnaev knew nothing about the attacks before they happened. He didn't respond to e-mailed requests today seeking an interview with her or comment on the DNA finding.
The discovery of genetic material was reported earlier today by the Wall Street Journal.
Tamerlan Tsarnaev, 26, and his brother are suspected by U.S. authorities of setting off bombs at the Boston Marathon finish line that killed three people and wounding 260. Dzhokhar Tsarnaev, 19, was apprehended on April 19 after a manhunt that paralyzed the Boston metropolitan area. He was found hiding in a boat in the backyard of a Watertown, Massachusetts, home and taken to the hospital for treatment of gunshot wounds.
The younger Tsarnaev, now being held at a federal prison west of Boston for inmates needing medical care, is charged with using and conspiring to use a weapon of mass destruction in the double bombing.
To contact the reporter on this story: Phil Mattingly in Washington at pmattingly@bloomberg.net
To contact the editor responsible for this story: Steven Komarow at skomarow1@bloomberg.net
