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Fingerprint examiners use a variety of terms and phrases to describe a finding of a match between a defendant's fingerprints and fingerprint impressions collected from a crime scene. Despite the importance and ubiquity of fingerprint evidence in criminal cases, no prior studies examine how jurors evaluate such evidence. We present two studies examining the impact of different match phrases, method descriptions, and statements about possible examiner error on the weight given to fingerprint identification evidence by laypersons. In both studies, the particular phrase chosen to describe the finding of a match-whether simple and imprecise or detailed and claiming near certainty-had little effect on participants' judgments about the guilt of a suspect. In contrast, the examiner admitting the possibility of error reduced the weight given to the fingerprint evidence-regardless of whether the admission was made during direct or cross-examination. In addition, the examiner providing information about the method used to make fingerprint comparisons reduced the impact of admitting the possibility of error. We found few individual differences in reactions to the fingerprint evidence across a wide range of participant variables, and we found widespread agreement regarding the uniqueness of fingerprints and the reliability of fingerprint identifications. Our results suggest that information about the reliability of fingerprint identifications will have a greater impact on lay interpretations of fingerprint evidence than the specific qualitative or quantitative terms chosen to describe a fingerprint match.

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Several forensic sciences, especially of the pattern-matching kind, are increasingly seen to lack the scientific foundation needed to justify continuing admission as trial evidence. Indeed, several have been abolished in the recent past. A likely next candidate for elimination is bitemark identification. A number of DNA exonerations have occurred in recent years for individuals convicted based on erroneous bitemark identifications. Intense scientific and legal scrutiny has resulted. An important National Academies review found little scientific support for the field. The Texas Forensic Science Commission recently recommended a moratorium on the admission of bitemark expert testimony. The California Supreme Court has a case before it that could start a national dismantling of forensic odontology. This article describes the (legal) basis for the rise of bitemark identification and the (scientific) basis for its impending fall. The article explains the general logic of forensic identification, the claims of bitemark identification, and reviews relevant empirical research on bitemark identification—highlighting both the lack of research and the lack of support provided by what research does exist. The rise and possible fall of bitemark identification evidence has broader implications—highlighting the weak scientific culture of forensic science and the law's difficulty in evaluating and responding to unreliable and unscientific evidence.

Fingerprint examiners regularly participate in tests designed to assess their proficiency. These tests provide information relevant to the weight of fingerprint evidence, but no prior research has directly examined how jurors react to proficiency testing information. Using a nationally representative sample of American adults, we examined the impact of proficiency testing information on the weight given to the opinions of fingerprint examiners by mock jurors considering a hypothetical criminal case. The fingerprint examiner's level of performance on a proficiency test (high, medium, low, or very low), but not the type of error committed on the test (false positive identifications, false negative identifications, or a mix of both types of error), affected the weight that jury‐eligible adults gave to an examiner's opinion that latent fingerprints recovered from a crime scene matched the defendant's fingerprints, which in turn affected judgments about the defendant's guilt. Jurors who had no information about proficiency gave similar weight to the testimony as jurors exposed to highly proficient examiners, suggesting that jurors assume fingerprint examiners perform at high levels of proficiency unless informed otherwise. We also found that a plurality of Americans deems false acquittals just as aversive as false convictions and a significant minority deems false acquittals more serious. These differences in error aversions predicted differences in evidentiary assessments, suggesting that error aversions of jurors may play an important role in criminal trials.