Another part of the answer involves the limitations of the verification systems available in 1997.

Biometric comparison was less sophisticated and less routinely applied than it later became.

The specific forensic technique of ear comparison was known but not standard practice in missing persons cases.

Bourdin’s own fingerprints should theoretically have been checkable against whatever records existed of Frédéric Bourdin in European law enforcement databases.

But this check was apparently not performed — or not performed in a way that produced the right result — for more than a year after his arrival in San Antonio.

When Parker’s tip sent Bourdin’s fingerprints to Interpol, the match came back quickly.