The reporters seem to know who the 3rd person is, but they won't name him.
And Dan Abrams said he knows; he also asked today about the "material," whatever it is, being found in a house where a person lives, so I'm thinking it is one of the two specimens that they found in the bathroom -- NOT ON HER -- that the SBI lab found "inconclusive."
BTW, the news this morning (on FOX) was the DNA was sampled in a "tissue fragment" of microscopic size found on one of the fingernails.