Skip to content

The Critical Role of Statistics in Demonstrating the Reliability of Expert Evidence

Journal: Fordham Law Review
Published: 2018
Primary Author: Karen Kafadar
Research Area: Latent Print

Federal Rule of Evidence 702, which covers testimony by expert witnesses, allows a witness to testify “in the form of an opinion or otherwise” if “the testimony is based on sufficient facts or data” and “is the product of reliable principles and methods” that have been “reliably applied.” The determination of “sufficient” (facts or data) and whether the “reliable principles and methods” relate to the scientific question at hand involve more discrimination than the current Rule 702 may suggest. Using examples from latent fingerprint matching and trace evidence (bullet lead and glass), I offer some criteria that scientists often consider in assessing the “trustworthiness” of evidence to enable courts to better distinguish between “trustworthy” and “questionable” evidence. The codification of such criteria may ultimately strengthen the current Rule 702 so courts can better distinguish between demonstrably scientific sufficiency and “opinion” based on inadequate (or inappurtenant) methods.

Related Resources

How Minutiae Frequency is Perceived and Used by Fingerprint Analysts in the Evaluation of Fingerprint Evidence

How Minutiae Frequency is Perceived and Used by Fingerprint Analysts in the Evaluation of Fingerprint Evidence

Analysts consider the appearance, placement, and number of features within a fingerprint pattern (called minutiae) that correspond when deciding whether two fingerprints originated from the same person. Little is known…
Analyzing spatial responses: A comparison of IRT- based approaches

Analyzing spatial responses: A comparison of IRT- based approaches

We investigate two approaches for analyzing spatial coordinate responses using models inspired by Item Response Theory (IRT). In the first, we use a two-stage approach to first construct a pseudoresponse…
Perceptions of blind proficiency testing among latent print examiners

Perceptions of blind proficiency testing among latent print examiners

In recent years, scholars have levied multiple criticisms against traditional proficiency testing procedures in forensic laboratories. Consequently, on several occasions, authorities have formally recommended that laboratories implement blind proficiency testing…
What types of information can and do latent print examiners review? A survey of practicing examiners

What types of information can and do latent print examiners review? A survey of practicing examiners

Understanding typical work practices is important to understanding the decision-making process underlying latent print comparison and improving the reliability of the discipline. Despite efforts to standardize work practices, a growing…