Beliefs about error rates and human judgment in forensic science

Abstract

Forensic science techniques are often used in criminal trials to infer the identity of the perpetrator of crime and jurors often find this evidence very persuasive. Unfortunately, two of the leading causes of wrongful convictions are forensic science testing errors and false or misleading forensic testimony (Saks & Koehler, 2005). Therefore, it is important to understand jurors' pre-existing beliefs about forensic science, as these beliefs may impact how they evaluate forensic evidence in the courtroom. In this study, we examine people's perceptions of the likelihood of error and human judgment involved at each stage of the forensic science process (i.e., collection, storage, testing, analysis, reporting, and presenting). In addition, we examine people's perceptions of the accuracy of -and human judgment involved in -16 different forensic techniques. We find that, in contrast to what would be expected by the CSI effect literature, participants believed that the process of forensic science involved considerable human judgment and was relatively error-prone.In addition, participants had wide-ranging beliefs about the accuracy of various forensic techniques, ranging from 65.18% (document analysis) up to 89.95% (DNA). For some forensic techniques, estimates were lower than that found in experimental proficiency studies, suggesting that our participants are more skeptical of certain forensic evidence than they need to be.

Forensic Confirmation Bias: Do Jurors Discount Examiners Who Were Exposed to Task‐Irrelevant Information?*†

“…Yet, they are likewise vulnerable to cognitive bias (e.g., [3,56,57]). Moreover, laypeople seem to view bitemark and fingerprint evidence as equally compelling: Koehler (38) found that laypeople believed both fingerprint and bitemark identification errors to be exceptionally rare (1 in 5.5 million and 1 in 1 million, respectively), and Ribeiro et al (58) found that laypeople perceived fingerprint and bitemark identification as equally accurate (88% vs. 89%, respectively) and as entailing a comparable degree of subjective judgment.…”

Improving Expert Evidence: The Role of Open Science and Transparency

“…249 Recent empirical research reinforces the view that the public is beginning to see the forensic sciences as less believable. 250 The ways in which forensic science's two most closely allied fields (i.e., mainstream science and law) have dealt with issues of trust may be instructive. In science, the open science movement is surely very much about the reliability and democratization of knowledge.…”

Increasing engagement of forensic pathologists with the public on social media: Could there be room for live broadcasts?

“…It is best to be able to explain these issues outside of the intense glare and emotion of high profile cases, when tests and investigations not essential to making a determination of the cause and manner of death may be performed if only to settle the publics reservations about the integrity of the entire process Given the imperative to educate the public about the functions of forensic pathologists within the medicolegal and public health surveillance systems, why not seize the opportunity to fundamentally alter how we communicate by engaging with the public? Are the often inaccurate depictions of forensic pathology on television and in the movies, not sufficient motivation for us to educate potential jurors about the capabilities and limitations of contemporary forensic pathology [ 4 , 5 ]? Even though many forensic pathologists are not attached to medical centers nor are they for a variety of reasons involved in research [ 6 ], are we as a community maximizing opportunities to disseminate what research we are involved in to a public and a scientific community that in many ways funds this research and expects evidence based decisions in our reports and in our testimony?…”