Mistaking Good Faith

The Fourth Amendment’s exclusionary rule is barreling towards obsolescence.&nbsp; One reason is the ever-broadening good faith exception, which prevents suppression whenever officers aren’t “culpable” enough for the deterrence benefits to outweigh the costs.&nbsp; The doctrine so far has insulated searches based on faulty recordkeeping and later-invalidated legal authorities.&nbsp; But it lacks a limiting principle.&nbsp; It’s thus likely to metastasize into a version of “legal deference” akin to Chevron or qualified immunity: illegally obtained evidence will be admitted wherever officers reasonably misinterpreted their own authority.&nbsp; Lower courts are already so holding.&nbsp;&nbsp;<br><br> That’s a serious problem.&nbsp; Legal deference has been excoriated as abetting misconduct, amplifying legal ambiguity, and undermining judicial authority.&nbsp; And if applied to the exclusionary rule, such deference would functionally eliminate the rule’s deterrent effect—its only remaining purpose.<br><br> To avoid this fate, we need a better organizing principle.&nbsp; This article supplies one: the criminal law doctrine of mistake.&nbsp; Mistake doctrine forgives criminal behavior based on non-culpable mistakes of fact or later-invalidated official legal interpretations, but not personal legal errors.&nbsp; It closely tracks good faith’s current scope, it’s grounded in the same principles of culpability and utilitarianism, and it’s designed to eliminate the problems of improper legal deference.&nbsp; And mistake doctrine’s justifications apply at least as forcefully to police activity.&nbsp; Thus, the good faith exception should be interpreted through the lens of mistake doctrine to justify its current scope and constrain its future expansion.