Of course, prosecutors have essentially the same power, since they’re under no obligation to bring charges against even an obviously guilty defendant. But while the power of juries to let guilty people go free in the name of justice is treated as suspect and called “jury nullification,” the power of prosecutors to do the exact same thing is called “prosecutorial discretion,” and is treated not as a bug, but as a feature in our justice system. But there’s no obvious reason why one is better than the other. Yes, prosecutors are professionals — but they’re also politicians, which means that their discretion may be employed politically. And they’re repeat players in the justice system, which makes them targets for corruption in a way that juries — laypeople who come together for a single case — aren’t.