Complex sentence: As with Frey's previous book, it was marketed as a memoir, but after its release large parts of the story were cast into doubt, and the author later admitted that he had never actually been incarcerated as claimed in the book.
Split into simpler sentences: As with Frey's previous book, it was marketed as a memoir, but after its release, certain elements of the story were cast into doubt. The author later admitted that he had never actually been incarcerated as claimed in the book.