This is the infamous A-Framed House talked about concerning a potential spot Maura may have been taken too. My understanding is that search dogs hit on a scent in this house of possible human remains said:
Thanks for all your hard work! I'm not sure, but I seem to recall reading something about the scent in this abandoned house being attributed to old menstrual blood that had been in a clothes hamper back when somebody used to live there.
I have absolutley no idea how anybody could have come to this conclusion, and I don't remember whether or not that was the official conclusion from the investigators, but I know it's something that I read.
Maybe they never tied the scent to Maura, but I don't see how they could rule it out, either.
ETA: Not to get too graphic at all, but I kind of have to for this part. I've always hoped that cadaver dogs would be cross trained to be able to distinguish scents like menstrual blood from a decomposing body, and from whatever I read about this building, it seems that they somehow thought they had done that in this case. However, while watching the Casey Anthony trial, I was surprised to hear one of the experts testify that, along with rags that have been kept in human chest cavities, one of the items they use to train cadaver dogs is placenta! As soon as I heard this I began to wonder how handlers would know the difference between menstrual blood and a dead body if their dogs are trained to hit on placenta. Apparently they are cross-trained NOT to hit on rotting meat from animals and not to hit on any other scent but human remains AND placenta. So, it sounded like the dogs would give the same alert. Really makes me curious about how anyone figured that this was from a laundry hamper. Having said all this, I'm SURE there's an explanation and that if the dog trainer had been asked to elaborate on the placenta he might have gone into detail about how they rule out menstrual blood, because I'm SURE it comes up. If they don't have a way to distinguish between the two, they're in for a lot of problems, so who knows....