After birth, the ear grows in size but maintains its essential proportional shape.

By early childhood, the ear’s distinctive ridges, curves, and proportions are essentially fixed.

This means that a high-quality photograph of someone’s ear taken at age ten and a photograph taken at age twenty should show the same essential ear shape, scaled up.

The proportions of the helix (the outer curved rim), the antihelix (the inner ridge), the tragus, and the various folds and depressions that give each ear its individual character should be consistent between photographs taken years apart.

When Parker compared photographs of Nicholas Barclay — pre-disappearance photos from the family’s collection — with photographs of Bourdin as “Nicholas” in San Antonio, the ear shapes did not match.