Jury nullification occurs when jurors choose not to convict a defendant they believe to be guilty of the offense charged, usually because they conclude that the law in question is unjust or the punishment is excessive. When I first thought about jury nullification as a young law student, I was inclined to be against it. Yes, it could potentially be used to curb unjust laws. But it can also be a vehicle for jury prejudice and bias. Most notoriously, all-white juries in the Jim Crow-era South often acquitted blatantly guilty white defendants who had committed racially motivated crimes against blacks. Moreover, it seems unfair if Defendant A gets convicted while Defendant B is acquitted after committing exactly the same offense, merely because B was lucky enough to get a jury that disapproves of the underlying law.

I still think these standard objections to nullification have some merit. But I now give much more credence to the opposing case. In this recent USA Today column, legal scholar Glenn Reynolds provides a strong defense of nullification. As he points out, the sort of discretion exercised by nullifying jurors has much in common with prosecutorial discretion and can be justified by many of the same considerations:

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.

As Reynolds points out, jury nullification is supported by longstanding Anglo-American legal tradition, and was considered a vital check on government power by many of the Founders. The case for jury nullification today is strengthened by the enormous growth of modern criminal law, which has expanded to the point where almost all of us are guilty of some crime or other (an issue that Reynolds himself has written about). In a world where almost everyone is a criminal, there is already enormous arbitrariness, because prosecutors can only go after only a small percentage of the many perpetrators. Jury nullification is unlikely to make that situation worse than it already is.

Moreover, many of the crimes on the books are ones that either should not be illegal at all, or should not carry such harsh penalties. As a practical matter, jury nullification is much more likely to target those kinds of laws than ones that rest on a broad social consensus to the effect that the activities they ban should be criminalized and violators subjected to severe punishment.

The racial, ethnic, and religious prejudice that made nullification dangerous in earlier eras certainly has not completely disappeared. But it has greatly diminished. That reduces, even if it does not eliminate, a key downside of nullification.

Jury nullification is far from a complete solution to the problem of overcriminalization. It would be better to simply remove many of these laws from the books entirely. But nullification can help improve the situation at the margin. For that reason, among others, I am much more sympathetic to it than I used to be.

UPDATE: It is worth noting that Reynolds’ column was partly inspired by a recent case where a jury nullification advocate was charged with jury tampering for handing out pro-nullification leaflets outside a courthouse. For reasons that co-blogger Eugene Volokh explains here, such prosecutions likely violate the First Amendment.

UPDATE #2: I should also note that my limited support for jury nullification is not in tension with my opposition to mandatory jury service, and my concern that jurors will decide some cases badly because of ignorance. Whether jury service is mandatory (as in the status quo) or voluntary (as I advocate), jury nullification can still help combat unjust laws at the margin. And even if jurors might nullify some good laws out of ignorance, this has to be weighed against the reality that a high proportion of the criminal laws currently on the books are dubious, at best.