Who Are You?

In 1879, a young police clerk in Paris named Alphonse Bertillon proposed a solution to a problem that had plagued law enforcement for decades: how do you know if the person in front of you is who they say they are? Before photographs were cheap to reproduce and before fingerprint databases existed, professional criminals could simply give a false name and walk free. Bertillon’s answer was anthropometry: measure the skull, the length of the forearm, and other bodily dimensions that, taken together, were statistically unlikely to be identical in any two people. The system spread across Europe, the United States, and colonies in Asia and Africa, and was the first large-scale attempt to use the body as a database. Anthropometry had a fundamental weakness: measurements had to be taken correctly by trained operators. By 1900 fingerprinting was replacing it almost everywhere because fingerprints were more reliable and required less skill to record. But the desire of states and institutions…