The Exclusionary Rule and "Unknown" Evidence
Do Exclusionary Rules Convict the Innocent?The abstract didn't do much to clarify.
Rules excluding various kinds of evidence from criminal trials play a prominent role in criminal procedure, and have generated considerable controversy. In this paper, we address the general topic of excluding factually relevant evidence, that is, the kind of evidence that would rationally influence the jury’s verdict if it were admitted. We do not offer a comprehensive analysis of these exclusionary rules, but add to the existing literature by identifying a new domain for economic analysis, focusing on how juries respond to the existence of such a rule. We show that the impact of exclusionary rules on the likelihood of conviction is complex and depends on the degree of rationality exhibited by juries and on the motivations of the prosecutor.
While my reaction after reading the abstract was that this was merely another attempt to manufacture controversy over nothing in the hope of making a pointless law review article slightly provocative, and getting more than the usual 12 readers, I noted that Berman, breaking with his normal tradition, actually included a few words of substantive commentary:
I have long thought that significant concern about wrongful convictions and significant support for the exclusionary rule were in some conceptual tension, and this paper appears to play out some of these kind of ideas. Though I certainly believe it can be a principled supporter of the exclusionary rule while expressing vocal concerns about wrongful convictions, I think supporters of the exclusionary rule should acknowledge that they sometimes favor putting procedural concerns ahead of trial accuracy.
Dang, now I had to actually read the article and get a sense of why there might be some validity to this position. To save you from the burden, here's my quick and dirty: Jurors know that crucial evidence gets excluded at trial because of "technicalities," so they assume that there is damning evidence that the judge won't let them see and convict based on the imaginary evidence when the evidence that is admitted isn't strong enough.
And you know, it's not as weird as it first appears.
While there's no basis to believe that this happens in every case, nor even in the majority of cases, every trial lawyer who has talked to jurors after the verdict knows that they come up with wild ideas in the jury room that no one would ever anticipate. That such ideas would include the assumption that every trial involves excluded evidence seems pretty natural.
It's wrong, of course, for jurors to assume that in every case there is hard evidence proving the defendant guilty that the court has withheld from them because of that nasty technicality we call the Constitution. First, it's remarkably rare that any evidence is subject to the exclusionary rule, suppression of physical evidence, statements or identification occurring so rarely given the wealth of exceptions to the various constitutional protections.
But second, to conceive of exclusion as some trick, some technicality designed to keep damning evidence form the eyes of the factfinder, reflects a serious misapprehension of the situation. Indeed, even Berman's commentary seems to make this blunder:
I think supporters of the exclusionary rule should acknowledge that they sometimes favor putting procedural concerns ahead of trial accuracy.
Procedural concerns? Hardly. Sure, the exclusion of evidence sometimes implicates trial accuracy, particularly when we're talking about physical evidence. But what about a suggestive identification? To allow its introduction at trial doesn't further trial accuracy. Just the opposite. Or coerced statements? Again, no trial accuracy to be had there.
It strikes me that there is a rhetorical argument to be made that every aspect of the law offers an opportunity, often from some cynical perspective, for damage to a party. Sure, the judge will instruct the jury not to speculate about evidence that doesn't come before them, and the instruction will be heard and either ignored or misapprehended like so many other instructions given. It might carry some greater weight if judges didn't simultaneously allow evidence under the guise of background, or completing the narrative, that is otherwise irrelevant, immaterial, or unreliable. But that would make prosecutions more difficult, and nobody would want to prevent the prosecution from getting as much of its story in there as possible, even if it's nothing more than a story.
In the scheme of things, however, this is not a trade-off of trial accuracy against procedure, but a means of vindicating the Constitution and addressing its violations. Since it happens to rarely, the fact that jurors might assume that there is secret bad evidence withhold from them in every case is bizarre, and might well merit a special instruction that there is no terrible evidence that would prove guilt but has been concealed from them. It might not be true on the rare occasion that suppression was granted, but since the jurors are likely to ignore the instruction anyway, no harm would follow.
Yet accommodating juror speculation by eliminating exclusion, and thereby eliminating the wild notion that this secret unknown damning evidence exists and is being withheld, is like using an elephant gun to shoot a mouse. While a conceptual possibility, and perhaps even a real cause of a jury convicting an innocent person based on imaginary evidence, the need to address constitutional violations is far more real and prevalent. This is hardly just some slavishness toward procedure, but the only means available to protect us from the government violating our constitutional rights.
To the extent the problem exists, perhaps a solution is needed. Eliminating exclusion, however, is hardly the answer.