Nicholas Barclay disappeared in San Antonio, TX. Three years later he was found in Spain, but was this the real Nicholas?

Sources:

The Imposter

60 Minutes Australia: Mystery of Missing Boy Nicholas Barclay and his Imposter Frederic Bourdin

The Nicholas Barclay Disappearance And Ensuing Deception | Missing | Investigation Discovery

Frédéric Bourdin - Wikipedia

Nicholas Patrick Barclay – The Charley Project

Interview: The private detective who uncovered The Imposter (scotsman.com)

The Mystery Of Nicholas Barclay And His Imposter, Frédéric Bourdin (allthatsinteresting.com)

Justice for Nicholas Barclay - The CrimeWire

The Chameleon | The New Yorker

Frederic Bourdin: The Crazy True Story Of A Serial Impostor (grunge.com)