This is another book off WSJ reviewer Tom Nolan's Best Mystery Books of 2019 list. Six down, four to go.
Tom has a pretty broad definition of "mystery". There's a negligible amount of whodunit content here. But that's OK. It's a page-turner.
Right from page one, we learn that the first-person narrator, Rafael Zhettah, is keeping a couple of people, Sarah and Leonard, locked up. A countdown timer shows how much time is left on their "sentence" (initially 2,444 days). Rafael provides them a TV (stuck on CNN, 16 hours/day, now that's cruel and unusual punishment). And he addresses them as "your honors". Hm.
How did that happen? We find out eventually. Pre-kidnapping, Rafael was on death row, convicted of the brutal murder of his billionaire wife. He's innocent (see the title), but thanks to a lazy investigation, zealous prosecution, and a weak alibi… sorry, Rafael, get ready for your Pentobarbital injection.
Given the prologue, we know that Rafael gets out, and (somehow) decides to exact revenge on Sarah and Leonard, and the path is a twisty one.
The author, David R. Dow, is an active opponent of the death penalty, founder and director of the Texas Innocence Network. So there's some advocacy here mixed in with the plot. Depending on your own feelings about capital punishment, you can either roll your eyes or punch the air in agreement.
As said, the book's a page-turner, but strains credulity at times. The biggest disbelief-suspending hurdle for me: Rafael just happens to own a bit of Kansas property that has an unusual plot-critical feature, undisclosed until page 167. No spoilers here, but geez, I said, isn't that convenient?