Evaluating the Credibility Using Prior Convictions: An Empirical Study of Rule 609 and Suggestions for Practical Reform

Abstract

Rule 609 of the Federal Rule of Evidence allows a party to impeach a witness with his or her prior criminal convictions. It is fair to say that this rule is the most criticized of all the Rules of Evidence; scholars have been calling for its reform or outright abolition for decades. These critics argue that the rule relies on propensity evidence which has very little probative value in evaluating a witness’s truthfulness on the stand, and that — especially when used to impeach a criminal defendant — the evidence carries a high risk of unfair prejudice and often prevents defendants from testifying at trial. What has been missing from the debate so far is what is actually happening when judges apply Rule 609 in the courtroom. This article conducts an empirical study of Rule 609 in order to determine how the rule operates in practice. It first presents the results of a survey of law students and federal district court judges to determine how much probative value and unfair prejudice each group perceives exist for different types of prior convictions. The survey finds some differences between the groups, but overall it notes a surprising consensus that crimes of theft have a high probative value for proving lack of credibility, while other types of conviction do not. The article then examines how federal district court judges are actually applying Rule 609 in the courtroom. Contrary to the conventional wisdom, it shows that federal court judges do not routinely admit prior convictions to impeach criminal defendants, and that (consistent with the survey) judges tend to admit theft crimes more often than almost any other type of conviction. The review of district court decisions does indicate some extreme outliers and an unexplained and troubling tendency to admit crimes of drug possession. Thus, the conclusion of the article proposes a modest reform to Rule 609, which encourages the admission of theft crimes to impeach witnesses, but precludes the use of other types of criminal convictions as impeachment evidence.