The Chameleon: The many lives of Frederic Bourdin.
This was in Best American Nonrequired Reading and it was so fascinating. And kind of haunting. It’s about this man who pretended to be young kids and then pretended to be the missing son of this American family for a long time and it’s just all very twisted and strange.
Of course, you probably don’t want to read 13 pages online so you should probably just buy this book because everything else has been equally as good. Lots of really interesting nonfiction.