The exposure — through ear comparison and fingerprint matching — came from the application of techniques that treated identity as a matter of physical fact rather than social agreement.

Ears don’t change shape because everyone agrees you are someone else.

Fingerprints don’t change because a grieving family needs them to.

The case illustrates the tension between identity as social construction and identity as biological fact — a tension that is normally invisible because the two usually coincide, but that becomes stark when someone like Bourdin deliberately exploits the gap between them.

The Hundred Identities