Jury Instructions on Witness Identification

One of the most important things a judge does when presiding over a jury trial is instruct jurors on the law. No doubt judges themselves are well-versed in the law, and the language of jury instructions is the source of much pre-deliberation wrangling on the part of the attorneys. Yet once judges settle on proper instructions, how effectively do they communicate the law to jurors? What can courts do to make jury instructions more effective? Do judges’ nonverbal actions, as well as their words, influence jury decisions? These questions come up in any jury trial, but they are particularly important in trials relying heavily on witness-identification testimony, for six reasons. First, misidentifications are the most common cause of false convictions. Second, jurors have strong intuitions about the factors that make witness identifications more or less accurate, and many of those intuitions are erroneous. Third, judges themselves have limited knowledge about the factors that do and do not affect identification accuracy. Fourth, a vast amount of empirical research has been conducted on witness identification, giving judges a unique opportunity to guide juror decision making so that it comports with relevant data on the issue. Fifth, testimony about witness identifications can often be quite technical— especially if it involves expert testimony, as these cases increasingly do—placing challenges on juror decision making. And sixth, traditional procedural safeguards designed to reduce false identifications and convictions—such as voir dire, motions to suppress suggestive identifications, and cross-examination— have only limited effectiveness. Thus, judges are well situated to aid jurors in making proper use of witness-identification testimony