Actually, correct me if I am wrong, but when men buy underwear it is usually in hermetically sealed packaging, depending on the type I suppose. But women's and girls underwear seems to always hang out on racks where people can touch it as it sits there. Suppose it was hanging there in the store and then some guy with a cold happened to sneeze on it or something like that.

Did the underwear we are talking about come in hermetically sealed packaging? Was it with the panties for a week? or was it just by itself? Anyone know?

Also, suppose the panties were laden with DNA from the clerk/customer who sneezed into them like a handkerchief, and then JonBenet put them on, could the DNA be transferred that way to her fingernails?

Not that I think that is what happened but I am just imagining things.