Pamela Colloff knows a scam artist when she sees one, or so she thought.

As an award-winning reporter at ProPublica and a staff writer at The New York Times Magazine, as well as a former writer and executive editor of Texas Monthly, she's heard a lot of tall tales.

But when she talked to Paul Skalnik, a jailhouse informant serving time in a federal prison near Dallas, she was convinced that he wanted to work with her to tell his story.