The law and economics of the exclusionary rule.

• Author: Jacobi, Tonja

The exclusionary rule is premised on behavioral assumptions about how the law shapes police conduct. This Article uses a law and economics approach and formally models the implications of these assumptions. It shows: first, that in attempting to deter police violations, the rule does little to discourage police harassment of ordinary citizens, particularly minorities, potentially even leaving police with a dominant strategy to search; and second, when applied at trial, the rule decreases the benefit of the doubt received by defendants who are most likely to be actually innocent. Judicial attempts to mitigate these costs of the exclusionary rule in fact exacerbate them. The manifold jurisprudential rules that make up this area of law can be assessed in terms of the extent each effectively differentiates between the guilty and the innocent. Assessed in this way, it becomes clear that much of the secondary jurisprudence in search and seizure law further aggravates the problem. A means of assessing the appropriateness of this secondary jurisprudence is provided, that promotes better screening between innocent and guilty defendants.

INTRODUCTION I. THE EFFECTS OF THE EXCLUSIONARY RULE AT THE POLICING STAGE A. The Theory and Empirics of Deterrence--The Problem of Selection Bias B. Information and Incentives--Principal-Agent Problems C. Perjury and Aggressive Policing--Substitution Effects D. A Formal Economic Model of the Exclusionary Rule at the Policing Stage II. THE EFFECTS OF THE EXCLUSIONARY RULE IN THE COURT ROOM A. Implications from the Absence of Evidence B. Juror Resistance C. Juror Error D. Perverse Screening E. A Formal Economic Model of the Exclusionary Rule at the Trial Stage III. POSSIBLE SOLUTIONS AND THEM LIMITS A. Jury Instructions Are Not a Solution B. Mitigation Through Evidentiary Rules Is Not an Adequate Solution C. Amending the Exclusionary Rule Will Not Work D. Abolishing and Replacing the Exclusionary Rule E. Judicial Distortion of the Exclusionary Rule F. An Alternative Approach CONCLUSION INTRODUCTION

The exclusionary rule is the principal remedy of constitutional criminal procedure, and also its most controversial element. For many, the notion of refusing to allow juries to consider relevant evidence because of police misconduct is anathema to the nature and purpose of juridical inquiry. (1) but it is arguably also the only way to deter constitutional violations. (2) The existing literature centers on these normative and empirical questions, but neither has brought any resolution, nor are they considered likely to do so. (3) This Article provides a new approach, applying a law and economics analysis to the exclusionary rule, which allows for a reassessment of its costs and benefits. Rigorously drawing out the implications of the Supreme Court's behavioral assumptions unveils additional costs that the rule imposes. Most significantly, this Article shows first, that the exclusionary rule is unlikely to be effective under most realistic conditions--and thus its benefits are questionable--and second, that its costs fall overwhelmingly on innocents, both defendants and non-defendants. This same analysis provides a means of assessing the secondary doctrinal components of search and seizure law and a mechanism for reforming the most harmful effects of the exclusionary rule.

The exclusionary rule was developed as an automatic and binary mechanism whereby evidence is admitted or not admitted, depending on the violation of a fixed constitutional line, regardless of the substantive unfairness to the defendant or the probative value of the evidence. But after its initial development (4) and the broadening of its application to all the states, (5) the Supreme Court has gradually narrowed the rule through the institution of a number of exceptions, including exempting knock-and-announce violations, (6) creating a good-faith exception for court administrators, (7) and extending that exception to police officers in certain circumstances. (8) The Roberts Court has determined that future application of the exclusionary rule will depend on whether its value in terms of deterring police from constitutional violations is deemed to outweigh the social costs to the justice system. (9) These costs are traditionally assessed in terms of lost arrests, inefficient prosecutions, and lost convictions, but there are additional costs imposed by the exclusionary rule, both at the policing and trial stages.

In terms of policing, the exhaustive literature challenging whether the exclusionary rule actually deters police from violating the Fourth Amendment, and whether its costs overwhelm its benefits, can be understood in terms of established law and economics phenomena: selection bias, principal-agent problems, moral hazard, and avoidance through substitution. First, the rule provides a remedy only for defendants where incriminating evidence was actually found against them--those who are thus most likely to be actually guilty-and fails to provide any remedy to citizens against whom unconstitutional searches were conducted where no such evidence was found-those most likely to be actually innocent. All of the doctrine is based on this selection bias, reinforcing the focus on defendants incriminated by searches, and providing protection to non-defendants, or defendants exculpated by searches, only through a jurisprudential trickle-down effect of protection. (10) But the interests of guilty and innocent defendants are not often the same. Second, exclusion is a penalty intended to deter police from future violations, but it offers no punishment for police harassing innocent citizens who are not ultimately prosecuted. (11) or for police who mistakenly rather than intentionally violate constitutional rights. This creates principal-agent problems, distorting the motivations of even well-intentioned officers. Third, consequently, the rule encourages police perjury and aggressive policing, two substitution effects that undermine the rule's operation. The overall result is that police incentives are not as the Supreme Court presumes they are.

By formally modeling how the exclusionary rule operates within the context of actual police incentives, I show that while the exclusionary rule can deter some searches, it will not do so under typical conditions. In fact, the exclusionary rule only works as the Court claims under very unusual circumstances, requiring police to place very little value on getting drugs or weapons off the street; furthermore, the police may still have a dominant strategy to search under other conditions, even if exclusion of evidence is guaranteed. As such, the exclusionary rule does not have the deterrent effect that the Court claims it does.

At the trial stage, the exclusionary rule operates to prevent evidence from ever reaching the jury, (12) but jurors make inferences from other evidence and trial procedure, and deduce the operation of the rule. Accordingly, they discount the prosecution's burden of proof-and the defendant's right to reasonable doubt--by an estimate of the effect of the rule. But the inaccuracy inherent in this process means that defendants for whom the exclusionary rule has not in fact been exercised will be systematically penalized. I show that exclusion of tainted evidence does not simply return defendants to their neutral positions, but for an illegal search. Rather, the exclusionary rule benefits defendants most likely to be guilty at the expense of the actually innocent--the exclusionary rule actually decreases the chance of finding a reasonable doubt for those defendants most likely to be innocent.

The well-worn debate over the exclusionary rule is framed in terms of the extent we should be willing to allow the guilty to go free so as to expansively interpret the rights of accused criminals. Setting the guilty free is an accepted price for both long-range deterrence against police violations of constitutional rights, as well as the expressive commitment to fairness in the criminal justice system. (13) However, wrongly convicting the innocent is not part of that deal. The proverbial ten guilty men are not meant to be set free for their own sake, but rather so that the one innocent person goes free. (14) This Article establishes that by instituting constitutional protections for actually guilty criminal suspects, the exclusionary rule creates a higher burden of proof for actually innocent defendants. As such, the vast literature justifying or criticizing the exclusionary rule for the extent to which it treads the correct balance for guilty suspects misses the most vital point.

There are a number of reasons why these additional costs have not been appreciated by prior scholars. First, because the rule is now justified exclusively in terms of its deterrence effect, (15) the courts and the literature have focused almost exclusively on the deterrent effect of the rule at the policing stage. However, what happens at the trial stage determines whether the incentives the Court assumes will actually exist. Second, economic analysis is seldom applied to constitutional criminal procedure; however, it is extremely useful, as it reveals the implications of the behavioral assumptions that the Supreme Court routinely makes. Unlike most of constitutional law, which is interpreted with reference to such fundamentals as the Constitution's text, structure, and the framers' intent, constitutional criminal procedure is based on behavioral assumptions. Yet the empirical evidence of deterrence is highly disputed. (16) The economic analysis in this Article shows that the exclusionary rule is not simply ineffective and costly, but it undermines the foundation of the criminal justice system in sorting innocent and guilty defendants. Finally, because the exclusionary rule is only visible with respect to criminal defendants, some commentators have reframed the Fourth Amendment right of all citizens...