"Meanwhile, all the rewards for the prosecutor, at any level, are for making more prisoners. Since most prosecutors are elected, they might seem responsive to democratic discipline. In truth, they are so easily reëlected that a common path for a successful prosecutor is toward higher office. And the one thing that can cripple a prosecutor's political ascent is a reputation, even if based on only a single case, for being too lenient. In short, our system has huge incentives for brutality, and no incentives at all for mercy."
Adam Gopnik at The New Yorker reviews John F. Pfaff's Locked In: The True Causes of Mass Incarceration and How to Achieve Real Reform.
As does German Lopez at Vox.