Investigators have discovered female DNA on one of the bombs used in the horrific attack at the Boston Marathon—but don’t jump to conclusions. It’s not clear who the DNA belongs to, or even if the person played a part in helping the Tsarnaev brothers carry out their attack. There are several explanations as to why a woman’s DNA—or anyone’s, for that matter—could be found on the bomb’s exploded remnants. Perhaps the person worked at a store where parts of the bomb were purchased, or her hair could’ve landed on the device after the explosion. FBI agents were, however, at the Rhode Island home of Katherine Russell, Tamerlan Tsarnaev’s widow, on Monday reportedly to collect a DNA sample.