Female DNA has been found on at least one of the bombs used in the Boston Marathon attacks, according to a new report. But it isn’t clear if that means a woman helped suspects Tamerlan and Dzhokhar Tsarnaev carry out the attacks. U.S. officials told The Wall Street Journal there could be several explanations for the DNA, including that it could have come from a store clerk who handled the materials the two brothers allegedly used in the bombings. A stray hair that landed on one of the explosives could also explain the DNA finding.