The Chameleon is a 2010 film directed by JeanPaul Salom and cowritten with Natalie Carter. The screenplay is based upon the true story of Frdric Bourdin who impersonated a missing child named Nicholas Barclay in San Antonio, Texas, in the 1990s. Much of the true story was incorporated into the film although the years have been altered and the location was moved to Baton Rouge, Louisiana.
He is reunited with his family who immediately have their suspicions regarding his story. His mother Ellen Barkin and half brother Brendan Nick Stahl do not seem to accept him, and many questions are open regarding whether this man could in fact be their lost family member, considering he does not look anything like the boy who left and now talks with a French accent. His sister Kathy Emilie de Ravin accepts his story without hesitation and eventually so does his possible mother.F.B.I. Agent Jennifer Johnson Famke Janssen strongly suspects that he is lying because she has had extensive experiences with people lying to her, including a man who was a child murderer whom she had dated. Meanwhile, his story starts to unravel and the true story of what happened to Nicholas starts to emerge. ........
Source: Wikipedia