Asymmetries and incentives in plea bargaining and evidence production.

• Author: Levmore, Saul

ESSAY CONTENTS INTRODUCTION I. LIMITS ON INDUCEMENTS TO TESTIFY A. The Ban on Payment for Testimony B. Monetary Versus Nonmonetary Inducements 1. The Holdout Problem and Other Dangers 2. Holdouts and Ex Ante Payments C. Explaining the State's Asymmetrical Advantage II. PAYMENTS FOR EVIDENCE PRODUCTION A. Ex Ante and Ex Post Payments B. Regulated Payments for Physical Evidence 1. The Need for Greater Rewards 2. One Step Forward C. Distinguishing Regulated Payments for Testimony CONCLUSION INTRODUCTION

The law of evidence is full of puzzles. Many of these revolve around admissibility and, more narrowly, the rules forbidding or restricting payment to a fact witness. (1) Presumably, the dangers of self-interest and perjury are thought to dominate the benefits normally associated with remuneration for hard work. At the same time, the government--but not the defense--is able to reward witnesses in criminal cases with certain nonmonetary inducements, including agreements to seek reduced penalties, or even not to prosecute at all in both related and unrelated cases. (2) If a witness is already incarcerated, the government can offer to improve the conditions of confinement. (3) This asymmetry is something of a puzzle, for most asymmetries in criminal law favor the defendant. The asymmetry seems to disappear when physical evidence is at issue. Both prosecutors and defendants, and even potential defendants, can within limits encourage the production of physical evidence with monetary rewards, though of course pieces of evidence (like testimony) can also be judicially compelled and thus need not be purchased. (4) The ability of even interested defendants to pay for physical evidence is sensible rather than doubly puzzling if one regards the dangers of bias and false testimony as much reduced in the case of physical evidence. At the same time, this permissiveness with respect to one kind of evidence raises the question of why we do not see more payments (or requests for payment) for things like privately owned surveillance devices that could generate important evidence.

One goal of this Essay is to develop the idea that a better understanding of the particular distaste for monetary incentives and of the asymmetry in favor of the government leads to a conclusion that law could better encourage the production of evidence. Law's focus has been on the rules of evidence gathering in the investigation of crimes and accusations. We suggest that optimal crime fighting, as well as the preservation of individual rights, likely involves greater private investment in strategies that are set in motion before specific crimes are committed. Our positive theorizing about several asymmetries in inducements to produce evidence--monetary/nonmonetary, prosecution/defense, testimonial/physical--has important implications for the question of how to encourage the production of evidence and thus the accuracy of verdicts and the efficient reduction of crime. (5) In the process, we offer a number of explanations for the existing and superficially troubling asymmetries. (6)

Part I analyzes the first two asymmetries. We begin with the prohibition on monetary payments to witnesses, and note the allowances for informants who are not quite, or not yet, witnesses in court. Private parties and governments can, for instance, offer rewards for information leading to arrests, and both can establish rewards for whistleblowers. Payments that facilitate the recovery of stolen property are also permitted, though these might generate testimonial evidence. Disallowed payments should be understood in the shadow of litigants' power to compel testimony from identifiable witnesses. At the same time, monetary payments might undermine civic virtue and encourage false testimony. We suggest that none of these features is as useful an explanatory device as the idea that monetary payments would often give witnesses monopoly, or holdout, power.

The discussion then turns to the asymmetry between the prosecution and the defense. The prosecution's superior ability to encourage witnesses can be understood as manifesting the public's preference for fighting crime and its indifference to the rights of likely defendants. Moreover, the public is likely to prefer inexpensive crime fighting, and it thus supports a system that bars monetary payments but allows plea bargains, which seem costless. The prosecution/defense asymmetry is a product of this preference. An orthogonal explanation for the asymmetry begins with the requirement that inducements to witnesses be disclosed so that their testimony can be properly evaluated. The prosecution, as a repeat player, is likely more reliable than defendants, though perhaps no more so than public defenders, in complying with a duty to disclose; moreover, the benefits the prosecution offers to witnesses are more observable than are those that defendants would offer. A final explanation regards the government's ability to plea bargain with potential witnesses as a means of offsetting the disinclination of many witnesses to be disloyal to their employers and friends.

Part II turns from the gathering of evidence to its production. We begin with the apparent distinction between a payment made before particular testimony is sought and one made ex post, when it is known to concern a particular accused or to favor one side in a specific criminal case. This distinction turns out to play an important role in understanding where monetary payment is permitted. The ex ante/ex post distinction incorporates a strategy for discouraging false testimony and minimizing the danger that wellplaced witnesses, including experienced inmates and informants, would initiate crimes in order to profit from them.

The explanations of the monetary/nonmonetary asymmetry do not extend to physical evidence. It is, for example, more difficult to fabricate a murder weapon or a damning digital image than it is to provide false testimony. Moreover, inasmuch as physical evidence is more easily compelled than is testimonial evidence, there is less of a holdout problem. There remains the problem of encouraging the production of evidence, and for this, we turn in part to the law of takings for guidance. It is likely that there is underproduction of physical evidence, and that judicious payments to those who provide physical evidence or even some subsidy of individuals' use of new technologies would be worthwhile. The Essay concludes with a summary of policy implications and limitations.

1. LIMITS ON INDUCEMENTS TO TESTIFY

   1. The Ban on Payment for Testimony

      Criminal laws pertaining to bribery, the rules of evidence, and the rules of professional responsibility combine to limit payments to witnesses. (7) At one end of the spectrum, expert witnesses can be paid for their time, and in this manner earn a return on their training. (8) Even run-of-the-mill fact witnesses can generally be compensated for time and travel. (9) But at the other end, no payment can be conditioned on "the giving of testimony in a certain way," no payment can be made to prevent or discourage a witness from testifying, and none can be contingent on the outcome of the case. (10)

      One can imagine a legal system permitting payments in order to encourage fact witnesses, especially if they have reason to be afraid or if the truth to which they will testify is unpopular. (11) But it is plain that most legal systems, and certainly relevant American law, reflect the view that profit will hazardously generate falsehoods. (12) The nearly universal strategy is to permit both sides to enlist the help of a court in order to compel witnesses to testify, but not to use money to encourage unidentifiable witnesses to step forward, to encourage reluctant witnesses to be more forthcoming, or to encourage the production of physical evidence that would not otherwise come into being.

      However universal this strategy may be, it comes with exceptions, mostly directed at payments made long before a trial or specific crime takes place. Thus, one source of exception is the convention, or sporadic practice, of offering a reward for information leading to the arrest of a perpetrator or to the return of a stolen item. In the process of collecting the reward, a potential witness might be identified and in this way, even if eventually compelled to testify, effectively paid for testimony. At a minimum, rewards for information rather than testimony could be challenged at trial as part of an objection to the admissibility of evidence, including a prior approval of an intrusive search. It is, therefore, somewhat surprising that these rewards do not appear to have generated litigation when the information encouraged in this manner had an impact on actual testimony.

      The information-testimony connection is not entirely overlooked. A lawyer in search of an alibi witness would probably not dare post the advertisement: "I will pay $1,000 for a witness who saw the person pictured below in East Los Angeles on Friday, the 3rd of March." But, of course, lawyers and investigators regularly grease information pathways, so that there are some payments that lead to testimony. Moreover, the hypothetical advertisement just sketched would be conventional rather than daring if it avoided the word witness and simply asked for information about its featured subject. It is difficult to obtain systematic information about related practices, but police surely modify their investigations when a suspect provides credible information pointing to a new theory of a crime, and such information can often be developed through rewards. Still, it seems safe to proceed under the assumption that the world of criminal trials would look different if payments for testimony were explicitly permitted. Both sides might wish to offer payments ex post, and the government (and perhaps insurers) would likely offer payments ex ante in order to increase the production of evidence. (13)...