We’ve all heard of the rule of lenity — that is, the arguably abandoned idea that ambiguous criminal laws should be construed in favor of private defendants. The traditional rule of lenity is largely grounded in the idea that private citizens should be given notice of what the law does and does not proscribe. In recent years, however, the Supreme Court seems to have implemented a different kind of leniency. This new principle calls for leniency not toward private defendants, but rather toward police. Let’s call it the other rule of lenity.
The other rule of lenity is most visible in the Court’s recent attitude toward Fourth Amendment remedies. The standard for penetrating qualified immunity has been rigorously enforced and perhaps even heightened. The result is that it is much harder to obtain relief in civil lawsuits against police, even when the police acted unlawfully. The Court has likewise strengthened the “good faith” exception to the exclusionary rule, thereby insulating law-enforcement from a major potential consequence of illegal searches. Much as with the traditional rule, the other rule of lenity is concerned with giving adequate notice — not to private citizens trying to stay on the right side of the law, but rather to police exercising their investigative powers. There is an obvious tension here, for treating the police leniently can have severe consequences for defendants.
What are we to make of having a pro-suspect rule of lenity when it comes to interpreting criminal statutes at trial, and an analogous pro-officer rule when it comes to the scope of police investigation? Perhaps this situation is merely a reflection of the Court’s increasing sympathies with police and apathy toward defendants. That realpolitik answer would explain both the decline of traditional lenity and the rise of its counterpart. Alternatively, there may be good reasons to apply lenity differently in connection with investigation as opposed to trials. For instance, we might think it important to cast the investigative net widely in order to capture persons who, once detected, are indisputably engaged in unlawful and perhaps dangerous conduct. By contrast, it might make sense to err on the side of freedom when trying defendants whose actions might not have been criminal at all.
The tension between the two rules of lenity is about to become more acute. Last month, the Court granted cert in Heien v. North Carolina. To simplify somewhat, Hein involves a police officer who detained a driver based on a non-existent crime. That sounds obviously unconstitutional, but the officer’s error may have been reasonable given state-law ambiguities at the time of the stop. Heien seems to provide a very clean presentation of the disparity between the two lenity principles. When interpreting the specific criminal prohibition at issue in Heien, North Carolina courts were presumably obliged to apply the traditional rule of lenity. The question now is whether lenity switches to the other side of the “v.” when police have acted unlawfully in light of that very same criminal prohibition.