Looking for a short story about a man who is investigating a spate of shoplifting in a small town. The local business people are close to panic as merchandise seems to vanish without a clue.
Eventually the investigator catches the perpetrator who turns out to be a disturbed young woman. We find that the investigator and the shoplifter are part of the next stage of human evolution and — along with others of their kind — have developed a protective ability that allows them to go unnoticed amongst Homo sapiens. This ability had allowed the shoplifting woman to steal completely unobserved.
Part of a short story collection, can’t remember when I read it.