I don't know, but it's a pretty good one.
" . . . Bryan Stevenson took home the Carnegie Medal in nonfiction for Just Mercy: A Story of Justice and Redemption (Spiegel & Grau). And he gave a timely acceptance speech that had many librarians in attendance buzzing about the best book award acceptance speech they'd ever heard."
i read the book in June (based on the recommendation of Somebody here on BL -- I would love to remember who), and it was an outstanding and thought-provoking read.
Here's one paragraph from Mr. Stevenson's speech:
"I wrote this book because I was persuaded that if people saw what I see, they would insist on something different. And that's what's powerful about books. That's what great about the library. Getting people closer to worlds and situations that they can't otherwise know and understand. I think there's real power in that. And that's what books can do."
click the link to read it in its entirety.