Stranger

This case could be loosely based on Frédéric "The Chameleon" Bourdin, who was a French serial impostor who in 1997 impersonated a missing Texas boy named Nicholas Barclay, who had gone missing 3 years prior. Bourdin claimed that he had been taken by a sex trafficker and suffered trauma and abuse over the 3 years he had been missing, and that was why he couldn't quite remember everything. He lived with the family for over 6 months before a P.I. became suspicious and ran his DNA to confirm his suspicions. After Bourdin was discovered, he claimed that the reason the Barclay family went along with the ruse was because someone in the family had murdered the little boy. Nicholas has never been found and his disappearance remains a mystery.

When the doctor says that type A blood is the only possible type for Heather because both her parents have A blood, he is not completely correct. If both parents also have the "O" allele, there is a 25% chance that she could have type O blood.