Authorities Said to Find Female DNA on Boston Bomb Piece

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 open case.